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I was working on a coding challenge where the goal was to find the smallest time difference in a list of Strings. I gave up and looked at a solution which in all makes sense, but I'm confused on the method parseTime. Can anybody please explain this method?
As I see it, the two hours compared are subtracted and then multiplied by 60 (becuase 60 min in one hour?).
From that the minutes are compared and then I get lost.. Can anybody explain this as simple as possible?
public static void main(String[] args) {
String[] strings = {"10:00am", "11:45pm", "5:00am", "12:01am"};
int i = TimeDifference(strings);
System.out.println(i);
}
public static int TimeDifference(String[] strArr) {
int min = Integer.MAX_VALUE;
for (int i=0; i<strArr.length; i++) {
for (int j=0; j<strArr.length; j++) {
if (i != j) {
int time = parseTime(strArr[j], strArr[i]);
if (time < min) min = time;
}
}
}
return min;
}
private static int parseTime(String time1, String time2) {
int time = (parseHour(time2) - parseHour(time1))*60;
time += parseMin(time2) - parseMin(time1);
if (isMorning(time2) != isMorning(time1)) {
time += 12 *60;
} else if (time <= 0 ) {
time += 24 * 60;
}
return time;
}
private static int parseHour(String time) {
int hour = Integer.valueOf(time.split(":")[0]);
return ( hour == 12? 0: hour);
}
private static int parseMin(String time) {
return Integer.valueOf(time.split(":")[1].replaceAll("[^0-9]",""));
}
private static boolean isMorning(String time) {
String post = time.split(":")[1].replaceAll("[^a-z]","");
return post.toLowerCase().equals("am");
}
Try to debug your code in your mind. Please check my comments below:
int minutes = parseTime("10:00am", "11:45pm");
private static int parseTime(String time1, String time2) {
int minutes = (parseHour(time2) - parseHour(time1))*60;//(11 - 10) * 60 = 60 minutes
minutes += parseMin(time2) - parseMin(time1); //60 + 45 - 0 = 105 minutes
if (isMorning(time2) != isMorning(time1)) { // 10:00am is not morning but 11:45pm is morning
minutes += 12 *60; //so we have to add 12 hours(12 * 60 minutes)
} else if (minutes <= 0 ) {
minutes += 24 * 60;
}
return minutes;
}
This is about regular expressions (RegEx). Let's look at 11:45pm as an example, and break up parseTime:
int time = (parseHour(time2) - parseHour(time1))*60;
The first line makes use of parseHour, which makes use of split, which splits the string around matches of the given regular expression, ":", and then parses the string at index 0 as an integer.
The string "11:45pm" is split into a string array {"11", "45pm"}, and the integer 11 is returned.
time += parseMin(time2) - parseMin(time1);
The second line makes use of parseMin, which similarly splits the given string, but parses the string at index 1 instead. However, the string "45pm" cannot be parsed as an integer, because it contains the non-digits "pm", so we use replaceAll to replace any non-digits with empty strings.
replaceAll replaces each substring of this string that matches the given regular expression with the given replacement.
"[^0-9]" matches any single character not present in 0-9, which is all nondigits, so "45pm".replaceAll("[^0-9]", "") returns "45", which is then parsed as an integer.
The rest has been answered by others already.
Yes, the difference in hours are converted to minutes by multiplying by 60. Then using parseMin the difference in minutes are added to it.
Now we need it check if it is AM or PM. Example : if the times were 10:30 am and 1:35 pm. The actual time difference is +115 minutes.
After parseHour the time would have a value of -600 ((1-10)*60). Then after parseMin, time would be -595 (difference of 5 minutes added). Now we need to see if it is AM or PM. Since time1 is AM and time2 is PM, we add a difference of 12hrs. This is because the same time in AM and PM would differ by 12hrs.
After this the time would be (-605 + 720) = 115 minutes.
The case when time<=0. This is when time2 is before time1. example time1 be 10:35am and time2 be 10:30am. So the question is - how much time would it take to REACH 10:30am FROM 10:35am. Since it is alreaddy 10:35am and since we cannot go back in time, we need to wait till the next day(24 hrs) to reach 10:30am. So we add 24*60 minutes to the time, which would give -5 + (24*60)
I want to Calculate the average of three time in hh:mm:ss format . I tried the following code .
public String calculateAverageOfTime()
{
String timeInHHmmss = "08:00:00 08:00:00 08:00:00";
String[] split = timeInHHmmss.split(" ");
long hh = 0,mm = 0,ss = 0;
for (int i = 0; i < split.length; i++)
{
String[] split1 = split[i].split(":");
hh += Long.valueOf(split1[0].trim());
mm += Long.valueOf(split1[1].trim());
ss += Long.valueOf(split1[2].trim());
}
hh = hh / split.length ;
mm = mm / split.length ;
ss = ss / split.length ;
String hms = String.format("%02d:%02d:%02d", hh,mm,ss);
return hms;
}
This code works well. Is there any efficient way to do this ? . Any method available in Java API .
Your current code is not correct, try for example with input 08:00:00 08:00:00 09:30:00. As #StephenC said it, you cannot average times by averaging hour, minute, second components. Times are like base-60 numbers, you know, 60 seconds + 1 = 1:00 instead of 61.
This is correct, calculating the sum of seconds, then taking average and converting back to time:
public static String calculateAverageOfTime(String timeInHHmmss) {
String[] split = timeInHHmmss.split(" ");
long seconds = 0;
for (String timestr : split) {
String[] hhmmss = timestr.split(":");
seconds += Integer.valueOf(hhmmss[0]) * 60 * 60;
seconds += Integer.valueOf(hhmmss[1]) * 60;
seconds += Integer.valueOf(hhmmss[2]);
}
seconds /= split.length;
long hh = seconds / 60 / 60;
long mm = (seconds / 60) % 60;
long ss = seconds % 60;
return String.format("%02d:%02d:%02d", hh,mm,ss);
}
Using Date, SimpleDateFormat or Joda would make the code easier to understand, but I don't think it can be more efficient than this, as this code does strictly what you want to do, which is averaging a base-60 number.
As others have pointed out, beware of the precision loss when averaging.
You might also want to validate that the input string is in the correct format, otherwise the algorithm will break.
There is no single method in the Java API that will solve this problem. But there are some that will help.
What you need to do is to break the problem down into parts:
Convert time strings to numbers.
Average the numbers
Convert the average back to a time string.
The problems of converting a time string to a number and a number to a time string can be solved using the SimpleDateFormat class, or the 3rd-party Joda time class library. Or you could manually extract the hours/minutes/seconds component, convert each to an integer and then compute the number of seconds.
The problem of averaging 3 numbers can be solved with one line of Java ... though you need to beware of the fact that integer division truncates the result.
For the record, you cannot average 3 times by averaging their three components, as you current code tries to do. It doesn't make mathematical sense.
Something like this should work:
String timeInHHmmss = "08:00:00 08:00:00 08:00:00";
String[] split = timeInHHmmss.split(" ");
long sum = 0L;
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
for (int i = 0; i < split.length; i++)
{
sum += sdf.parse(split[i]).getTime();
}
Date avgDate = new Date((sum/split.length));
System.out.println("avg Date is:"+sdf.format(avgDate));
Convert to java.util.Date and then you can do all kinds of operations.
Check Simple Date Format and Date
Part of an assignment I have for a beginning Java class is to take a time entered in as a string and convert it (while rounding to the nearest quarter hour) to a double and store it in an array. The part I am having difficult with is what to do with the two integers I receive from the split method of the String class. How do I make the two integers into one double to use in the array? (So it would be like hours.minutes, or 5.25)
Here is a snippet of code from a program I am working on:
public static double convertClockOutTimes(String clockOut){
double convertedTimeOut = 0;
String time = clockOut;
int hours;
int minutes;
String[]splitFields;
splitFields = time.split(":");
hours = Integer.parseInt(splitFields[0]);
minutes = Integer.parseInt(splitFields[1]);
if (minutes <= 7)
{
minutes = 0;
}
else if (minutes >= 8 || minutes <= 22)
{
minutes = 15;
}
else if (minutes >= 23 || minutes <= 37)
{
minutes = 30;
}
else if (minutes >= 31 || minutes <= 53)
{
minutes = 45;
}
else
minutes = 0;
hours = hours + 1;
convertedTimeOut = //This is where I don't know what to do!!
return convertedTimeOut;
}
I think the trick is to use a bit of math here. You could always do the following:
double convertedTimeOut = Math.round(minutes / 15.0) * 0.25 + hours;
then you don't need the if-else tree to figure out the nearest quarter hour.
There are 15 minutes in a quarter hour, and a quarter hour is 0.25 hours. Using the formula above, you are dividing the minutes into how many quarters of an hour you've got (0-4), which you then multiply by how many hours are in a quarter hour. Then add that to the hours you've got.
Math.round just does the rounding for you.
I'm guessing what's giving you the most trouble is how to deal with the minutes. Try this:
double minutesAsDecimal = 0.01 * minutes;
So if the number of minutes was 24, you would end up with 0.24. I bet you'll know where to go from there.
Just as a side note, your if and else ifs are not doing what you think they are. But since it's homework.. Just take a closer look at your logic there.
Your conditions should be AND not OR:
if(minutes >= 8 && minutes <= 22)
Etc, or better yet, a single statement, simply
minutes = ((minutes + 7) % 15) * 15;
which calculates the rounding using arithmetic rather than logic.
I've been trying to convert a value of seconds (in a BigDecimal variable) to a string in an editText like "1 hour 22 minutes 33 seconds" or something of the kind.
I've tried this:
String sequenceCaptureTime = "";
BigDecimal roundThreeCalc = new BigDecimal("0");
BigDecimal hours = new BigDecimal("0");
BigDecimal myremainder = new BigDecimal("0");
BigDecimal minutes = new BigDecimal("0");
BigDecimal seconds = new BigDecimal("0");
BigDecimal var3600 = new BigDecimal("3600");
BigDecimal var60 = new BigDecimal("60");
(I have a roundThreeCalc which is the value in seconds so I try to convert it here.)
hours = (roundThreeCalc.divide(var3600));
myremainder = (roundThreeCalc.remainder(var3600));
minutes = (myremainder.divide(var60));
seconds = (myremainder.remainder(var60));
sequenceCaptureTime = hours.toString() + minutes.toString() + seconds.toString();
Then I set the editText to sequnceCaptureTime String.
But that didn't work. It force closed the app every time. I am totally out of my depth here, any help is greatly appreciated.
Is it necessary to use a BigDecimal? If you don't have to, I'd use an int or long for seconds, and it would simplify things a little bit:
hours = totalSecs / 3600;
minutes = (totalSecs % 3600) / 60;
seconds = totalSecs % 60;
timeString = String.format("%02d:%02d:%02d", hours, minutes, seconds);
You might want to pad each to make sure they're two digit values(or whatever) in the string, though.
DateUtils.formatElapsedTime(long), formats an elapsed time in the form "MM:SS" or "H:MM:SS" . It returns the String you are looking for. You can find the documentation here
You should have more luck with
hours = roundThreeCalc.divide(var3600, BigDecimal.ROUND_FLOOR);
myremainder = roundThreeCalc.remainder(var3600);
minutes = myremainder.divide(var60, BigDecimal.ROUND_FLOOR);
seconds = myremainder.remainder(var60);
This will drop the decimal values after each division.
Edit: If that didn't work, try this. (I just wrote and tested it)
public static int[] splitToComponentTimes(BigDecimal biggy)
{
long longVal = biggy.longValue();
int hours = (int) longVal / 3600;
int remainder = (int) longVal - hours * 3600;
int mins = remainder / 60;
remainder = remainder - mins * 60;
int secs = remainder;
int[] ints = {hours , mins , secs};
return ints;
}
Something really helpful in Java 8
import java.time.LocalTime;
private String ConvertSecondToHHMMSSString(int nSecondTime) {
return LocalTime.MIN.plusSeconds(nSecondTime).toString();
}
Here is the working code:
private String getDurationString(int seconds) {
int hours = seconds / 3600;
int minutes = (seconds % 3600) / 60;
seconds = seconds % 60;
return twoDigitString(hours) + " : " + twoDigitString(minutes) + " : " + twoDigitString(seconds);
}
private String twoDigitString(int number) {
if (number == 0) {
return "00";
}
if (number / 10 == 0) {
return "0" + number;
}
return String.valueOf(number);
}
I prefer java's built in TimeUnit library
long seconds = TimeUnit.MINUTES.toSeconds(8);
private String ConvertSecondToHHMMString(int secondtTime)
{
TimeZone tz = TimeZone.getTimeZone("UTC");
SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");
df.setTimeZone(tz);
String time = df.format(new Date(secondtTime*1000L));
return time;
}
This is my simple solution:
String secToTime(int sec) {
int seconds = sec % 60;
int minutes = sec / 60;
if (minutes >= 60) {
int hours = minutes / 60;
minutes %= 60;
if( hours >= 24) {
int days = hours / 24;
return String.format("%d days %02d:%02d:%02d", days,hours%24, minutes, seconds);
}
return String.format("%02d:%02d:%02d", hours, minutes, seconds);
}
return String.format("00:%02d:%02d", minutes, seconds);
}
Test Results:
Result: 00:00:36 - 36
Result: 01:00:07 - 3607
Result: 6313 days 12:39:05 - 545488745
If you want the units h, min and sec for a duration you can use this:
public static String convertSeconds(int seconds) {
int h = seconds/ 3600;
int m = (seconds % 3600) / 60;
int s = seconds % 60;
String sh = (h > 0 ? String.valueOf(h) + " " + "h" : "");
String sm = (m < 10 && m > 0 && h > 0 ? "0" : "") + (m > 0 ? (h > 0 && s == 0 ? String.valueOf(m) : String.valueOf(m) + " " + "min") : "");
String ss = (s == 0 && (h > 0 || m > 0) ? "" : (s < 10 && (h > 0 || m > 0) ? "0" : "") + String.valueOf(s) + " " + "sec");
return sh + (h > 0 ? " " : "") + sm + (m > 0 ? " " : "") + ss;
}
int seconds = 3661;
String duration = convertSeconds(seconds);
That's a lot of conditional operators. The method will return those strings:
0 -> 0 sec
5 -> 5 sec
60 -> 1 min
65 -> 1 min 05 sec
3600 -> 1 h
3601 -> 1 h 01 sec
3660 -> 1 h 01
3661 -> 1 h 01 min 01 sec
108000 -> 30 h
I like to keep things simple therefore:
int tot_seconds = 5000;
int hours = tot_seconds / 3600;
int minutes = (tot_seconds % 3600) / 60;
int seconds = tot_seconds % 60;
String timeString = String.format("%02d Hour %02d Minutes %02d Seconds ", hours, minutes, seconds);
System.out.println(timeString);
The result will be: 01 Hour 23 Minutes 20 Seconds
Duration from java.time
BigDecimal secondsValue = BigDecimal.valueOf(4953);
if (secondsValue.compareTo(BigDecimal.valueOf(Long.MAX_VALUE)) > 0) {
System.out.println("Seconds value " + secondsValue + " is out of range");
} else {
Duration dur = Duration.ofSeconds(secondsValue.longValueExact());
long hours = dur.toHours();
int minutes = dur.toMinutesPart();
int seconds = dur.toSecondsPart();
System.out.format("%d hours %d minutes %d seconds%n", hours, minutes, seconds);
}
Output from this snippet is:
1 hours 22 minutes 33 seconds
If there had been a non-zero fraction of second in the BigDecimal this code would not have worked as it stands, but you may be able to modify it. The code works in Java 9 and later. In Java 8 the conversion from Duration into hours minutes and seconds is a bit more wordy, see the link at the bottom for how. I am leaving to you to choose the correct singular or plural form of the words (hour or hours, etc.).
Links
Oracle tutorial: Date Time explaining how to use java.time.
Answer by lauhub showing the conversion from a Duration to days, hours, minutes and seconds in Java 8.
This Code Is working Fine :
txtTimer.setText(String.format("%02d:%02d:%02d",(SecondsCounter/3600), ((SecondsCounter % 3600)/60), (SecondsCounter % 60)));
A nice and easy way to do it using GregorianCalendar
Import these into the project:
import java.util.GregorianCalendar;
import java.util.Date;
import java.text.SimpleDateFormat;
import java.util.Scanner;
And then:
Scanner s = new Scanner(System.in);
System.out.println("Seconds: ");
int secs = s.nextInt();
GregorianCalendar cal = new GregorianCalendar(0,0,0,0,0,secs);
Date dNow = cal.getTime();
SimpleDateFormat ft = new SimpleDateFormat("HH 'hours' mm 'minutes' ss 'seconds'");
System.out.println("Your time: " + ft.format(dNow));
for just minutes and seconds use this
String.format("%02d:%02d", (seconds / 3600 * 60 + ((seconds % 3600) / 60)), (seconds % 60))
With Java 8, you can easily achieve time in String format from long seconds like,
LocalTime.ofSecondOfDay(86399L)
Here, given value is max allowed to convert (upto 24 hours) and result will be
23:59:59
Pros : 1) No need to convert manually and to append 0 for single digit
Cons : work only for up to 24 hours
I use this:
public String SEG2HOR( long lnValue) { //OK
String lcStr = "00:00:00";
String lcSign = (lnValue>=0 ? " " : "-");
lnValue = lnValue * (lnValue>=0 ? 1 : -1);
if (lnValue>0) {
long lnHor = (lnValue/3600);
long lnHor1 = (lnValue % 3600);
long lnMin = (lnHor1/60);
long lnSec = (lnHor1 % 60);
lcStr = lcSign + ( lnHor < 10 ? "0": "") + String.valueOf(lnHor) +":"+
( lnMin < 10 ? "0": "") + String.valueOf(lnMin) +":"+
( lnSec < 10 ? "0": "") + String.valueOf(lnSec) ;
}
return lcStr;
}
Here's my function to address the problem:
public static String getConvertedTime(double time){
double h,m,s,mil;
mil = time % 1000;
s = time/1000;
m = s/60;
h = m/60;
s = s % 60;
m = m % 60;
h = h % 24;
return ((int)h < 10 ? "0"+String.valueOf((int)h) : String.valueOf((int)h))+":"+((int)m < 10 ? "0"+String.valueOf((int)m) : String.valueOf((int)m))
+":"+((int)s < 10 ? "0"+String.valueOf((int)s) : String.valueOf((int)s))
+":"+((int)mil > 100 ? String.valueOf((int)mil) : (int)mil > 9 ? "0"+String.valueOf((int)mil) : "00"+String.valueOf((int)mil));
}
I know this is pretty old but in java 8:
LocalTime.MIN.plusSeconds(120).format(DateTimeFormatter.ISO_LOCAL_TIME)
I use this in python to convert a float representing seconds to hours, minutes, seconds, and microseconds. It's reasonably elegant and is handy for converting to a datetime type via strptime to convert. It could also be easily extended to longer intervals (weeks, months, etc.) if needed.
def sectohmsus(seconds):
x = seconds
hmsus = []
for i in [3600, 60, 1]: # seconds in a hour, minute, and second
hmsus.append(int(x / i))
x %= i
hmsus.append(int(round(x * 1000000))) # microseconds
return hmsus # hours, minutes, seconds, microsecond
i have tried the best way and less code but may be it is little bit difficult to understand how i wrote my code but if you good at maths it is so easy
import java.util.Scanner;
class hours {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double s;
System.out.println("how many second you have ");
s =input.nextInt();
double h=s/3600;
int h2=(int)h;
double h_h2=h-h2;
double m=h_h2*60;
int m1=(int)m;
double m_m1=m-m1;
double m_m1s=m_m1*60;
System.out.println(h2+" hours:"+m1+" Minutes:"+Math.round(m_m1s)+" seconds");
}
}
more over it is accurate !
Tough there are yet many correct answers and an accepted one, if you want a more handmade and systematized way to do this, I suggest something like this:
/**
* Factors for converting seconds in minutes, minutes in hours, etc.
*/
private static int[] FACTORS = new int[] {
60, 60, 24, 7
};
/**
* Names of each time unit.
* The length of this array needs to be FACTORS.length + 1.
* The last one is the name of the remainder after
* obtaining each component.
*/
private static String[] NAMES = new String[] {
"second", "minute", "hour", "day", "week"
};
/**
* Checks if quantity is 1 in order to use or not the plural.
*/
private static String quantityToString(int quantity, String name) {
if (quantity == 1) {
return String.format("%d %s", quantity, name);
}
return String.format("%d %ss", quantity, name);
}
/**
* The seconds to String method.
*/
private static String secondsToString(int seconds) {
List<String> components = new ArrayList<>();
/**
* Obtains each component and stores only if is not 0.
*/
for (int i = 0; i < FACTORS.length; i++) {
int component = seconds % FACTORS[i];
seconds /= FACTORS[i];
if (component != 0) {
components.add(quantityToString(component, NAMES[i]));
}
}
/**
* The remainder is the last component.
*/
if (seconds != 0) {
components.add(quantityToString(seconds, NAMES[FACTORS.length]));
}
/**
* We have the non-0 components in reversed order.
* This could be extracted to another method.
*/
StringBuilder builder = new StringBuilder();
for (int i = components.size() - 1; i >= 0; i--) {
if (i == 0 && components.size() > 1) {
builder.append(" and ");
} else if (builder.length() > 0) {
builder.append(", ");
}
builder.append(components.get(i));
}
return builder.toString();
}
The result is as following:
System.out.println(secondsToString(5_000_000)); // 8 weeks, 1 day, 20 hours, 53 minutes and 20 seconds
System.out.println(secondsToString(500_000)); // 5 days, 18 hours, 53 minutes and 20 seconds
System.out.println(secondsToString(60*60*24)); // 1 day
System.out.println(secondsToString(2*60*60*24 + 3*60)); // 2 days and 3 minutes
System.out.println(secondsToString(60*60*24 + 3 * 60 * 60 + 53)); // 1 day, 3 hours and 53 seconds
You can get this done easily using method overloading.
Here's a code I wrote to convert seconds to hours, minutes and seconds format.
public class SecondsAndMinutes {
public static void main(String[] args) {
String finalOutput = getDurationString(-3666);
System.out.println(finalOutput);
}
public static String getDurationString(int seconds) {
if(seconds <= 0) {
return "Add a value bigger than zero.";
}else {
int hours = seconds / (60*60);
int remainingOneSeconds = seconds % (60*60);
int minutes = remainingOneSeconds / 60;
int remainingSeconds = remainingOneSeconds % 60;
String x = Integer.toString(hours);
return x+"h " + getDurationString(minutes, remainingSeconds);
}
}
public static String getDurationString(int minutes, int seconds) {
if(seconds <= 0 && seconds > 59) {
return "Seconds needs to be within 1 to 59";
}else {
String y = Integer.toString(minutes);
String z = Integer.toString(seconds);
return y+"m "+z+"s";
}
}
}
I want to record the time using System.currentTimeMillis() when a user begins something in my program. When he finishes, I will subtract the current System.currentTimeMillis() from the start variable, and I want to show them the time elapsed using a human readable format such as "XX hours, XX mins, XX seconds" or even "XX mins, XX seconds" because its not likely to take someone an hour.
What's the best way to do this?
Use the java.util.concurrent.TimeUnit class:
String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes(millis),
TimeUnit.MILLISECONDS.toSeconds(millis) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);
Note: TimeUnit is part of the Java 1.5 specification, but toMinutes was added as of Java 1.6.
To add a leading zero for values 0-9, just do:
String.format("%02d min, %02d sec",
TimeUnit.MILLISECONDS.toMinutes(millis),
TimeUnit.MILLISECONDS.toSeconds(millis) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);
If TimeUnit or toMinutes are unsupported (such as on Android before API version 9), use the following equations:
int seconds = (int) (milliseconds / 1000) % 60 ;
int minutes = (int) ((milliseconds / (1000*60)) % 60);
int hours = (int) ((milliseconds / (1000*60*60)) % 24);
//etc...
Based on #siddhadev's answer, I wrote a function which converts milliseconds to a formatted string:
/**
* Convert a millisecond duration to a string format
*
* #param millis A duration to convert to a string form
* #return A string of the form "X Days Y Hours Z Minutes A Seconds".
*/
public static String getDurationBreakdown(long millis) {
if(millis < 0) {
throw new IllegalArgumentException("Duration must be greater than zero!");
}
long days = TimeUnit.MILLISECONDS.toDays(millis);
millis -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis);
StringBuilder sb = new StringBuilder(64);
sb.append(days);
sb.append(" Days ");
sb.append(hours);
sb.append(" Hours ");
sb.append(minutes);
sb.append(" Minutes ");
sb.append(seconds);
sb.append(" Seconds");
return(sb.toString());
}
long time = 1536259;
return (new SimpleDateFormat("mm:ss:SSS")).format(new Date(time));
Prints:
25:36:259
Using the java.time package in Java 8:
Instant start = Instant.now();
Thread.sleep(63553);
Instant end = Instant.now();
System.out.println(Duration.between(start, end));
Output is in ISO 8601 Duration format: PT1M3.553S (1 minute and 3.553 seconds).
Uhm... how many milliseconds are in a second? And in a minute? Division is not that hard.
int seconds = (int) ((milliseconds / 1000) % 60);
int minutes = (int) ((milliseconds / 1000) / 60);
Continue like that for hours, days, weeks, months, year, decades, whatever.
I would not pull in the extra dependency just for that (division is not that hard, after all), but if you are using Commons Lang anyway, there are the DurationFormatUtils.
Example Usage (adapted from here):
import org.apache.commons.lang3.time.DurationFormatUtils
public String getAge(long value) {
long currentTime = System.currentTimeMillis();
long age = currentTime - value;
String ageString = DurationFormatUtils.formatDuration(age, "d") + "d";
if ("0d".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "H") + "h";
if ("0h".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "m") + "m";
if ("0m".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "s") + "s";
if ("0s".equals(ageString)) {
ageString = age + "ms";
}
}
}
}
return ageString;
}
Example:
long lastTime = System.currentTimeMillis() - 2000;
System.out.println("Elapsed time: " + getAge(lastTime));
//Output: 2s
Note: To get millis from two LocalDateTime objects you can use:
long age = ChronoUnit.MILLIS.between(initTime, LocalDateTime.now())
Either hand divisions, or use the SimpleDateFormat API.
long start = System.currentTimeMillis();
// do your work...
long elapsed = System.currentTimeMillis() - start;
DateFormat df = new SimpleDateFormat("HH 'hours', mm 'mins,' ss 'seconds'");
df.setTimeZone(TimeZone.getTimeZone("GMT+0"));
System.out.println(df.format(new Date(elapsed)));
Edit by Bombe: It has been shown in the comments that this approach only works for smaller durations (i.e. less than a day).
Just to add more info
if you want to format like: HH:mm:ss
0 <= HH <= infinite
0 <= mm < 60
0 <= ss < 60
use this:
int h = (int) ((startTimeInMillis / 1000) / 3600);
int m = (int) (((startTimeInMillis / 1000) / 60) % 60);
int s = (int) ((startTimeInMillis / 1000) % 60);
I just had this issue now and figured this out
Shortest solution:
Here's probably the shortest which also deals with time zones.
System.out.printf("%tT", millis-TimeZone.getDefault().getRawOffset());
Which outputs for example:
00:18:32
Explanation:
%tT is the time formatted for the 24-hour clock as %tH:%tM:%tS.
%tT also accepts longs as input, so no need to create a Date. printf() will simply print the time specified in milliseconds, but in the current time zone therefore we have to subtract the raw offset of the current time zone so that 0 milliseconds will be 0 hours and not the time offset value of the current time zone.
Note #1: If you need the result as a String, you can get it like this:
String t = String.format("%tT", millis-TimeZone.getDefault().getRawOffset());
Note #2: This only gives correct result if millis is less than a day because the day part is not included in the output.
I think the best way is:
String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toSeconds(length)/60,
TimeUnit.MILLISECONDS.toSeconds(length) % 60 );
Revisiting #brent-nash contribution, we could use modulus function instead of subtractions and use String.format method for the result string:
/**
* Convert a millisecond duration to a string format
*
* #param millis A duration to convert to a string form
* #return A string of the form "X Days Y Hours Z Minutes A Seconds B Milliseconds".
*/
public static String getDurationBreakdown(long millis) {
if (millis < 0) {
throw new IllegalArgumentException("Duration must be greater than zero!");
}
long days = TimeUnit.MILLISECONDS.toDays(millis);
long hours = TimeUnit.MILLISECONDS.toHours(millis) % 24;
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis) % 60;
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis) % 60;
long milliseconds = millis % 1000;
return String.format("%d Days %d Hours %d Minutes %d Seconds %d Milliseconds",
days, hours, minutes, seconds, milliseconds);
}
Joda-Time
Using Joda-Time:
DateTime startTime = new DateTime();
// do something
DateTime endTime = new DateTime();
Duration duration = new Duration(startTime, endTime);
Period period = duration.toPeriod().normalizedStandard(PeriodType.time());
System.out.println(PeriodFormat.getDefault().print(period));
For those who looking for Kotlin code:
fun converter(millis: Long): String =
String.format(
"%02d : %02d : %02d",
TimeUnit.MILLISECONDS.toHours(millis),
TimeUnit.MILLISECONDS.toMinutes(millis) - TimeUnit.HOURS.toMinutes(
TimeUnit.MILLISECONDS.toHours(millis)
),
TimeUnit.MILLISECONDS.toSeconds(millis) - TimeUnit.MINUTES.toSeconds(
TimeUnit.MILLISECONDS.toMinutes(millis)
)
)
Sample output: 09 : 10 : 26
My simple calculation:
String millisecToTime(int millisec) {
int sec = millisec/1000;
int second = sec % 60;
int minute = sec / 60;
if (minute >= 60) {
int hour = minute / 60;
minute %= 60;
return hour + ":" + (minute < 10 ? "0" + minute : minute) + ":" + (second < 10 ? "0" + second : second);
}
return minute + ":" + (second < 10 ? "0" + second : second);
}
Happy coding :)
Firstly, System.currentTimeMillis() and Instant.now() are not ideal for timing. They both report the wall-clock time, which the computer doesn't know precisely, and which can move erratically, including going backwards if for example the NTP daemon corrects the system time. If your timing happens on a single machine then you should instead use System.nanoTime().
Secondly, from Java 8 onwards java.time.Duration is the best way to represent a duration:
long start = System.nanoTime();
// do things...
long end = System.nanoTime();
Duration duration = Duration.ofNanos(end - start);
System.out.println(duration); // Prints "PT18M19.511627776S"
System.out.printf("%d Hours %d Minutes %d Seconds%n",
duration.toHours(), duration.toMinutes() % 60, duration.getSeconds() % 60);
// prints "0 Hours 18 Minutes 19 Seconds"
for Android below API 9
(String.format("%d hr %d min, %d sec", millis/(1000*60*60), (millis%(1000*60*60))/(1000*60), ((millis%(1000*60*60))%(1000*60))/1000))
For small times, less than an hour, I prefer:
long millis = ...
System.out.printf("%1$TM:%1$TS", millis);
// or
String str = String.format("%1$TM:%1$TS", millis);
for longer intervalls:
private static final long HOUR = TimeUnit.HOURS.toMillis(1);
...
if (millis < HOUR) {
System.out.printf("%1$TM:%1$TS%n", millis);
} else {
System.out.printf("%d:%2$TM:%2$TS%n", millis / HOUR, millis % HOUR);
}
Here is an answer based on Brent Nash answer, Hope that helps !
public static String getDurationBreakdown(long millis)
{
String[] units = {" Days ", " Hours ", " Minutes ", " Seconds "};
Long[] values = new Long[units.length];
if(millis < 0)
{
throw new IllegalArgumentException("Duration must be greater than zero!");
}
values[0] = TimeUnit.MILLISECONDS.toDays(millis);
millis -= TimeUnit.DAYS.toMillis(values[0]);
values[1] = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(values[1]);
values[2] = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(values[2]);
values[3] = TimeUnit.MILLISECONDS.toSeconds(millis);
StringBuilder sb = new StringBuilder(64);
boolean startPrinting = false;
for(int i = 0; i < units.length; i++){
if( !startPrinting && values[i] != 0)
startPrinting = true;
if(startPrinting){
sb.append(values[i]);
sb.append(units[i]);
}
}
return(sb.toString());
}
long startTime = System.currentTimeMillis();
// do your work...
long endTime=System.currentTimeMillis();
long diff=endTime-startTime;
long hours=TimeUnit.MILLISECONDS.toHours(diff);
diff=diff-(hours*60*60*1000);
long min=TimeUnit.MILLISECONDS.toMinutes(diff);
diff=diff-(min*60*1000);
long seconds=TimeUnit.MILLISECONDS.toSeconds(diff);
//hour, min and seconds variables contains the time elapsed on your work
This is easier in Java 9:
Duration elapsedTime = Duration.ofMillis(millisDiff );
String humanReadableElapsedTime = String.format(
"%d hours, %d mins, %d seconds",
elapsedTime.toHours(),
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
This produces a string like 0 hours, 39 mins, 9 seconds.
If you want to round to whole seconds before formatting:
elapsedTime = elapsedTime.plusMillis(500).truncatedTo(ChronoUnit.SECONDS);
To leave out the hours if they are 0:
long hours = elapsedTime.toHours();
String humanReadableElapsedTime;
if (hours == 0) {
humanReadableElapsedTime = String.format(
"%d mins, %d seconds",
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
} else {
humanReadableElapsedTime = String.format(
"%d hours, %d mins, %d seconds",
hours,
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
}
Now we can have for example 39 mins, 9 seconds.
To print minutes and seconds with leading zero to make them always two digits, just insert 02 into the relevant format specifiers, thus:
String humanReadableElapsedTime = String.format(
"%d hours, %02d mins, %02d seconds",
elapsedTime.toHours(),
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
Now we can have for example 0 hours, 39 mins, 09 seconds.
for correct strings ("1hour, 3sec", "3 min" but not "0 hour, 0 min, 3 sec") i write this code:
int seconds = (int)(millis / 1000) % 60 ;
int minutes = (int)((millis / (1000*60)) % 60);
int hours = (int)((millis / (1000*60*60)) % 24);
int days = (int)((millis / (1000*60*60*24)) % 365);
int years = (int)(millis / 1000*60*60*24*365);
ArrayList<String> timeArray = new ArrayList<String>();
if(years > 0)
timeArray.add(String.valueOf(years) + "y");
if(days > 0)
timeArray.add(String.valueOf(days) + "d");
if(hours>0)
timeArray.add(String.valueOf(hours) + "h");
if(minutes>0)
timeArray.add(String.valueOf(minutes) + "min");
if(seconds>0)
timeArray.add(String.valueOf(seconds) + "sec");
String time = "";
for (int i = 0; i < timeArray.size(); i++)
{
time = time + timeArray.get(i);
if (i != timeArray.size() - 1)
time = time + ", ";
}
if (time == "")
time = "0 sec";
If you know the time difference would be less than an hour, then you can use following code:
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
c2.add(Calendar.MINUTE, 51);
long diff = c2.getTimeInMillis() - c1.getTimeInMillis();
c2.set(Calendar.MINUTE, 0);
c2.set(Calendar.HOUR, 0);
c2.set(Calendar.SECOND, 0);
DateFormat df = new SimpleDateFormat("mm:ss");
long diff1 = c2.getTimeInMillis() + diff;
System.out.println(df.format(new Date(diff1)));
It will result to: 51:00
This answer is similar to some answers above. However, I feel that it would be beneficial because, unlike other answers, this will remove any extra commas or whitespace and handles abbreviation.
/**
* Converts milliseconds to "x days, x hours, x mins, x secs"
*
* #param millis
* The milliseconds
* #param longFormat
* {#code true} to use "seconds" and "minutes" instead of "secs" and "mins"
* #return A string representing how long in days/hours/minutes/seconds millis is.
*/
public static String millisToString(long millis, boolean longFormat) {
if (millis < 1000) {
return String.format("0 %s", longFormat ? "seconds" : "secs");
}
String[] units = {
"day", "hour", longFormat ? "minute" : "min", longFormat ? "second" : "sec"
};
long[] times = new long[4];
times[0] = TimeUnit.DAYS.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[0], TimeUnit.DAYS);
times[1] = TimeUnit.HOURS.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[1], TimeUnit.HOURS);
times[2] = TimeUnit.MINUTES.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[2], TimeUnit.MINUTES);
times[3] = TimeUnit.SECONDS.convert(millis, TimeUnit.MILLISECONDS);
StringBuilder s = new StringBuilder();
for (int i = 0; i < 4; i++) {
if (times[i] > 0) {
s.append(String.format("%d %s%s, ", times[i], units[i], times[i] == 1 ? "" : "s"));
}
}
return s.toString().substring(0, s.length() - 2);
}
/**
* Converts milliseconds to "x days, x hours, x mins, x secs"
*
* #param millis
* The milliseconds
* #return A string representing how long in days/hours/mins/secs millis is.
*/
public static String millisToString(long millis) {
return millisToString(millis, false);
}
There is a problem. When milliseconds is 59999, actually it is 1 minute but it will be computed as 59 seconds and 999 milliseconds is lost.
Here is a modified version based on previous answers, which can solve this loss:
public static String formatTime(long millis) {
long seconds = Math.round((double) millis / 1000);
long hours = TimeUnit.SECONDS.toHours(seconds);
if (hours > 0)
seconds -= TimeUnit.HOURS.toSeconds(hours);
long minutes = seconds > 0 ? TimeUnit.SECONDS.toMinutes(seconds) : 0;
if (minutes > 0)
seconds -= TimeUnit.MINUTES.toSeconds(minutes);
return hours > 0 ? String.format("%02d:%02d:%02d", hours, minutes, seconds) : String.format("%02d:%02d", minutes, seconds);
}
I have covered this in another answer but you can do:
public static Map<TimeUnit,Long> computeDiff(Date date1, Date date2) {
long diffInMillies = date2.getTime() - date1.getTime();
List<TimeUnit> units = new ArrayList<TimeUnit>(EnumSet.allOf(TimeUnit.class));
Collections.reverse(units);
Map<TimeUnit,Long> result = new LinkedHashMap<TimeUnit,Long>();
long milliesRest = diffInMillies;
for ( TimeUnit unit : units ) {
long diff = unit.convert(milliesRest,TimeUnit.MILLISECONDS);
long diffInMilliesForUnit = unit.toMillis(diff);
milliesRest = milliesRest - diffInMilliesForUnit;
result.put(unit,diff);
}
return result;
}
The output is something like Map:{DAYS=1, HOURS=3, MINUTES=46, SECONDS=40, MILLISECONDS=0, MICROSECONDS=0, NANOSECONDS=0}, with the units ordered.
It's up to you to figure out how to internationalize this data according to the target locale.
DurationFormatUtils.formatDurationHMS(long)
I modified #MyKuLLSKI 's answer and added plurlization support. I took out seconds because I didn't need them, though feel free to re-add it if you need it.
public static String intervalToHumanReadableTime(int intervalMins) {
if(intervalMins <= 0) {
return "0";
} else {
long intervalMs = intervalMins * 60 * 1000;
long days = TimeUnit.MILLISECONDS.toDays(intervalMs);
intervalMs -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(intervalMs);
intervalMs -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(intervalMs);
StringBuilder sb = new StringBuilder(12);
if (days >= 1) {
sb.append(days).append(" day").append(pluralize(days)).append(", ");
}
if (hours >= 1) {
sb.append(hours).append(" hour").append(pluralize(hours)).append(", ");
}
if (minutes >= 1) {
sb.append(minutes).append(" minute").append(pluralize(minutes));
} else {
sb.delete(sb.length()-2, sb.length()-1);
}
return(sb.toString());
}
}
public static String pluralize(long val) {
return (Math.round(val) > 1 ? "s" : "");
}
Use java.util.concurrent.TimeUnit, and use this simple method:
private static long timeDiff(Date date, Date date2, TimeUnit unit) {
long milliDiff=date2.getTime()-date.getTime();
long unitDiff = unit.convert(milliDiff, TimeUnit.MILLISECONDS);
return unitDiff;
}
For example:
SimpleDateFormat sdf = new SimpleDateFormat("yy/MM/dd HH:mm:ss");
Date firstDate = sdf.parse("06/24/2017 04:30:00");
Date secondDate = sdf.parse("07/24/2017 05:00:15");
Date thirdDate = sdf.parse("06/24/2017 06:00:15");
System.out.println("days difference: "+timeDiff(firstDate,secondDate,TimeUnit.DAYS));
System.out.println("hours difference: "+timeDiff(firstDate,thirdDate,TimeUnit.HOURS));
System.out.println("minutes difference: "+timeDiff(firstDate,thirdDate,TimeUnit.MINUTES));
System.out.println("seconds difference: "+timeDiff(firstDate,thirdDate,TimeUnit.SECONDS));
This topic has been well covered, I just wanted to share my functions perhaps you can make use of these rather than importing an entire library.
public long getSeconds(ms) {
return (ms/1000%60);
}
public long getMinutes(ms) {
return (ms/(1000*60)%60);
}
public long getHours(ms) {
return ((ms/(1000*60*60))%24);
}