Long converting to wrong time - java

I am trying to format a long until days, hours, minutes, seconds and found a method online.
public static String getTime(long time) {
long enlapsed = System.currentTimeMillis() - time;
long days = TimeUnit.MILLISECONDS.toDays(enlapsed);
enlapsed -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(enlapsed);
enlapsed -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(enlapsed);
enlapsed -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(enlapsed);
String result = days + "d " + hours + "h " + minutes + "m " + seconds + "s ";
return result.replace("0d ", "").replace("0h ", "").replace("0m ", "").replace("0s ", "");
}
and it was working but now suddenly inputting 4380 is giving 18151d 15h 33m 34s. What did I do wrong?

The method you found online calculates how much time has elapsed between now, and a given timestamp. You can test that this method works going to a site like this, and multiplying the timestamp by 1000 to convert it to milliseconds, and passing that long to getTime.
The timestamp 4380 represents 4380ms after the Java Epoch, which is approximately 1 January 1970, which is about 18000 days ago.
If you want a more recent example, the timestamp 1568312340000 is just a few minutes before I started writing this, and doing System.out.println(getTime(1568312340000L)); gives a smaller duration.
What you seem to want is not to calculate the elapsed time between now and a certain timestamp. You seem to just want to convert an amount of milliseconds to a duration expressed in days, hours, minutes and seconds.
The method works by first calculating the difference in milliseconds between now and the given timestamp, putting the difference into a variable called enlapsed (spelling mistake!) Then it calculates how many days, hours, minutes and seconds goes into enlapsed milliseconds. What you want is everything this method does except the first part where it calculates the difference, so you should delete this line:
long enlapsed = System.currentTimeMillis() - time;
and replace it with:
long enlapsed = time;
because you just want it to directly calculate what duration the time parameter represents.

An input of 4380 to your method would return the time from the epoch minus about 4 seconds. The epoch is 1970-01-01, so 18151 days/365.25 = 49.7 years - which in September of 2019 seems right to me.

Related

How to calculate relative time spans using Java (code converting problem)? [duplicate]

This question already has answers here:
Java 8: Difference between two LocalDateTime in multiple units
(11 answers)
Closed 2 years ago.
I decided to give myself a challenge on Java that implements this question's achievement.
The things I have to do is get LocalDateTime, convert the same code from the linked question's answers, then receiving a string from the function.
Here's what I've done so far:
public static String relTime(LocalDateTime now)
{
// accepted answer converted to Java
const int min = 60 * SECOND;
const int hour = 60 * MINUTE;
const int day = 24 * HOUR;
const int mon = 30 * DAY;
// still don't know how to convert this method
var ts = new TimeSpan(DateTime.UtcNow.Ticks - yourDate.Ticks);
double delta = Math.Abs(ts.TotalSeconds);
if (delta < 1 * MINUTE)
return ts.Seconds == 1 ? "one second ago" : ts.Seconds + " seconds ago";
if (delta < 2 * MINUTE)
return "a minute ago";
if (delta < 45 * MINUTE)
return ts.Minutes + " minutes ago";
if (delta < 90 * MINUTE)
return "an hour ago";
if (delta < 24 * HOUR)
return ts.Hours + " hours ago";
if (delta < 48 * HOUR)
return "yesterday";
if (delta < 30 * DAY)
return ts.Days + " days ago";
if (delta < 12 * MONTH)
{
int months = Convert.ToInt32(Math.Floor((double)ts.Days / 30));
return months <= 1 ? "one month ago" : months + " months ago";
}
else
{
int years = Convert.ToInt32(Math.Floor((double)ts.Days / 365));
return years <= 1 ? "one year ago" : years + " years ago";
}
}
The only problem that I should encounter is from var ts = new TimeSpan(DateTime.UtcNow.Ticks - yourDate.Ticks);.
Although I read 2 questions from Stack Overflow finding equivalents of TimeSpan and Ticks, I baely have any ideas how to properly convert the line of code. Also, I have to get a double which will need math.abs() to get TotalSeconds which I can't really find a proper way to deal with either, but I did find ZoneOffset.ofTotalSeconds and still don't know how to deal with it.
So how can I convert this properly?
var ts = new TimeSpan(DateTime.UtcNow.Ticks - yourDate.Ticks);
double delta = Math.Abs(ts.TotalSeconds);
You need to gain a deeper understanding of what this method actually does. Literally translating code from C# to Java won't give you a good solution and gets you stuck on language-specific details.
The two lines basically calculate the (absolute) difference in seconds of a timestamp to the current time. This can be written in Java as follows:
Duration duration = Duration.between(LocalDateTime.now(), timestamp);
long delta = duration.abs().getSeconds();
I'm just addressing your actual question here on how to transform these two lines. The provided snippet is not valid Java code and some parts are missing. delta is the difference in seconds which does not necessarily need to be a double. The argument you pass to your method should be named anything else than now because this is the timestamp you want to compare to the current time inside the method.
You could use SimpleDateFormat to create a nice display format (use something like "HH hours, mm minutes and ss seconds ago" for the format (not sure if this exact example works)). You could also use Instant to get the current time, and you can use Instant.now().minusSeconds(Instant.now().minusSeconds(seconds).getEpochSeconds()) for the time difference (or just use System.currentTimeMillis() and multiply by 1000).
Alternatively, you could use Duration and write a custom display format using getSeconds() and getHours() etc.

Joda-Time - Number of seconds between two dates

My english is not perfect, but I hope you can understand me.
I try to get the difference in seconds between two unix timestamps, but it's only return 0.
That's my code
unixOnline = Long.valueOf(online);
unixOffline = Long.valueOf(offline);
DateTimeZone BERLIN = DateTimeZone.forID("Europe/Berlin");
DateTime dateTimeOnline = new DateTime(unixOnline * 1000L, BERLIN);
DateTime dateTimeOffline = new DateTime(unixOffline * 1000L, BERLIN);
int seconds = Seconds.secondsBetween(new LocalDate(dateTimeOnline), new LocalDate(dateTimeOffline)).getSeconds();
System.out.println("Seconds: " + seconds);
Edit:
Online Timestamp: 1457536522
Offline Timestamp: 1457536642
LocalDate has no time component, so if the times are on the same day, they're effectively turned into the same time. Instead, just diff the DateTimes as they are;
int hours = Hours.hoursBetween(dateTimeOnline, dateTimeOffline).getHours();
(or in your case, since the difference is only 2 minutes, you'll only see the result with Minutes or Seconds)
EDIT: Since the question seems to have nothing to do with the time zone BERLIN which is in the code, this answer is a bit over complicated. Instead, use krzydyn's answer if it's just a time diff between UTC times.
Since you already have timestamps in seconds it can be simple calculated by formula:
int hours = (t2-t1)/3600;
Or if you need fractions:
float hours = (t2-t1)/3600f;
Update: (maybe I got suggested by the answer :)
So to get time diff in seconds is even simpler:
long seconds = t2-t1;

Represent date from long, starting from year 0 instead of 1970 [duplicate]

This question already has an answer here:
How to calculate difference between two dates in years...etc with Joda-Time
(1 answer)
Closed 8 years ago.
I have a long-variable which represents an amount of delay in milliseconds. I want to transform this long to some kind of Date where it says how many hours, minutes, seconds, days, months, years have passed.
When using Date toString() from Java, as in new Date(5).toString, it says 5 milliseconds have passed from 1970. I need it to say 5 milliseconds have passed, and 0 minutes, hours, ..., years.
you cannot get direct values , without any reference date for your requirements, you need define first reference value like below:
String dateStart = "01/14/2012 09:29:58";
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss")
Date d1 = format.parse(dateStart);
the above is your reference date , now you need to find the current date and time using following.
long currentDateTime = System.currentTimeMillis();
Date currentDate = new Date(currentDateTime);
Date d2.format(currentDate)
and the difference of these values like long diff=d2-d1 will gives values in milliseconds.
then
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);
and similarly for months and years.
you can also refer the example given on this link for more information http://javarevisited.blogspot.in/2012/12/how-to-convert-millisecond-to-date-in-java-example.html
From what I understand from your question you could achieve your goal by writing a method that will suit your needs i.e.:
static public String dateFromMili (long miliseconds) {
// constants that will hold the number of miliseconds
// in a given time unit (year, month etc.)
final int YEAR_IN_MILISECONDS = 12*30*24*60*60*1000;
final int MONTH_IN_MILISECONDS = 30*24*60*60*1000;
final int DAY_IN_MILISECONDS = 24*60*60*1000;
final int HOUR_IN_MILISECONDS = 60*60*1000;
final int MINUTE_IN_MILISECONDS = 60*1000;
final int SECONDS_IN_MILISECONDS = 1000;
// now use those constants to return an appropriate string.
return miliseconds +" miliseconds, "
+miliseconds/SECONDS_IN_MILISECONDS+" seconds, "
+miliseconds/MINUTE_IN_MILISECONDS+" minutes, "
+miliseconds/HOUR_IN_MILISECONDS+" hours, "
+miliseconds/DAY_IN_MILISECONDS+" days, "
+miliseconds/MONTH_IN_MILISECONDS+" months, "
+miliseconds/YEAR_IN_MILISECONDS+" years have passed";
}
Than you will have to pas the number of miliseconds as a parameter to your new function that will return the desired String (i.e for two seconds):
dateFromMili (2000);
You could also print your answer:
System.out.println(dateFromMili(2000));
The result would look like this:
2000 miliseconds, 2 seconds, 0 minutes, 0 hours, 0 days, 0 months, 0 years have passed
Note that this method will return Strings with integer value (you will not get for example "2.222333 years" but "2 years"). Furthermore, it could be perfected by changing the noun from plural to singular, when the context is appropriate ("months" to "month").
I hope my answer helped.
This is how I solved the problem:
I used a library called Joda-Time (http://www.joda.org/joda-time/) (credits to Keppil!)
Joda-Time has various data-structures for Date and Time. You can represent a date and time by a DateTime-object.
To represent the delay I was looking for, I had two options: a Period data-structure or a Duration data-structure. A good explanation of the difference between those two can be found here: Joda-Time: what's the difference between Period, Interval and Duration? .
I thus used a Duration-object, based on the current date of my DateTime-object. It has all the methods to convert the amount of milliseconds to years, months, weeks, days, hours, minutes and seconds.

milliseconds to days

i did some research, but still can't find how to get the days... Here is what I got:
int seconds = (int) (milliseconds / 1000) % 60 ;
int minutes = (int) ((milliseconds / (1000*60)) % 60);
int hours = (int) ((milliseconds / (1000*60*60)) % 24);
int days = ????? ;
Please help, I suck at math, thank's.
For simple cases like this, TimeUnit should be used. TimeUnit usage is a bit more explicit about what is being represented and is also much easier to read and write when compared to doing all of the arithmetic calculations explicitly. For example, to calculate the number days from milliseconds, the following statement would work:
long days = TimeUnit.MILLISECONDS.toDays(milliseconds);
For cases more advanced, where more finely grained durations need to be represented in the context of working with time, an all encompassing and modern date/time API should be used. For JDK8+, java.time is now included (here are the tutorials and javadocs). For earlier versions of Java joda-time is a solid alternative.
If you don't have another time interval bigger than days:
int days = (int) (milliseconds / (1000*60*60*24));
If you have weeks too:
int days = (int) ((milliseconds / (1000*60*60*24)) % 7);
int weeks = (int) (milliseconds / (1000*60*60*24*7));
It's probably best to avoid using months and years if possible, as they don't have a well-defined fixed length. Strictly speaking neither do days: daylight saving means that days can have a length that is not 24 hours.
Go for TImeUnit in java
In order to import use, java.util.concurrent.TimeUnit
long millisec=System.currentTimeMillis();
long seconds=TimeUnit.MILLISECONDS.toSeconds(millisec);
long minutes=TimeUnit.MILLISECONDS.toMinutes(millisec);
long hours=TimeUnit.MILLISECONDS.toMinutes(millisec);
long days=TimeUnit.MILLISECONDS.toDays(millisec);
java.time
You can use java.time.Duration which is modelled on ISO-8601 standards and was introduced with Java-8 as part of JSR-310 implementation. With Java-9 some more convenient methods were introduced.
Demo:
import java.time.Duration;
public class Main {
public static void main(String[] args) {
// Duration between the two instants
Duration duration = Duration.ofMillis(1234567890L);
// Print Duration#toString
System.out.println(duration);
// Custom format
// ####################################Java-8####################################
String formattedElapsedTime = String.format(
"%d Day %02d Hour %02d Minute %02d Second %d Millisecond (%d Nanosecond)", duration.toDays(),
duration.toHours() % 24, duration.toMinutes() % 60, duration.toSeconds() % 60,
duration.toMillis() % 1000, duration.toNanos() % 1000000000L);
System.out.println(formattedElapsedTime);
// ##############################################################################
// ####################################Java-9####################################
formattedElapsedTime = String.format("%d Day %02d Hour %02d Minute %02d Second %d Millisecond (%d Nanosecond)",
duration.toDaysPart(), duration.toHoursPart(), duration.toMinutesPart(), duration.toSecondsPart(),
duration.toMillisPart(), duration.toNanosPart());
System.out.println(formattedElapsedTime);
// ##############################################################################
}
}
A sample run:
PT342H56M7.89S
14 Day 06 Hour 56 Minute 07 Second 890 Millisecond (890000000 Nanosecond)
14 Day 06 Hour 56 Minute 07 Second 890 Millisecond (890000000 Nanosecond)
Learn more about the modern date-time API from Trail: Date Time.
int days = (int) (milliseconds / 86 400 000 )
public static final long SECOND_IN_MILLIS = 1000;
public static final long MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60;
public static final long HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60;
public static final long DAY_IN_MILLIS = HOUR_IN_MILLIS * 24;
public static final long WEEK_IN_MILLIS = DAY_IN_MILLIS * 7;
You could cast int but I would recommend using long.
You can’t. Sorry. Or more precisely: you can if you know a time zone and a start time (or end time). A day may have a length of 23, 24 or 25 hours or some other length. So there isn’t any sure-fire formula for converting from milliseconds to days. So while you can safely rely on 1000 milliseconds in a second, 60 seconds in a minute (reservation below) and 60 minutes in an hour, the conversion to days needs more context in order to be sure and accurate.
Reservation: In real life a minute is occasionally 61 seconds because of a leap second. Not in Java. Java always counts a minute as 60 seconds because common computer clocks don’t know leap seconds. Common operating systems and Java itself do know not only summer time (DST) but also many other timeline anomalies that cause a day to be shorter or longer than 24 hours.
To demonstrate. I am writing this on March 29, 2021, the day after my time zone, Europe/Copenhagen, and the rest of the EU switched to summer time.
ZoneId myTimeZone = ZoneId.of("Europe/Copenhagen");
ZonedDateTime now = ZonedDateTime.now(myTimeZone);
ZonedDateTime twoDaysAgo = now.minusDays(2);
ZonedDateTime inTwoDays = now.plusDays(2);
System.out.println(ChronoUnit.MILLIS.between(twoDaysAgo, now));
System.out.println(ChronoUnit.MILLIS.between(now, inTwoDays));
Output:
169200000
172800000
So how many milliseconds are in two days depends on which two days you mean. And in which time zone.
So what to do?
If for your purpose you can safely define a day as 24 hours always, for example because your days are counted in UTC or your users are fine with the inaccuracy, use either Duration or TimeUnit. Since Java 9 the Duration class will additionally tell you how many hours, minutes and seconds there are in addition to the whole days. See the answer by Arvind Kumar Avinash. For the TimeUnit enum see the answers by whaley and Dev Parzival. In any case the good news is that it doesn’t matter if you suck at math because the math is taken care of for you.
If you know a time zone and a starting point, use ZonedDateTime and ChronoUnit.DAYS. In this case too the math is taken care of for you.
ZonedDateTime start = LocalDate.of(2021, Month.MARCH, 28).atStartOfDay(myTimeZone);
long millisToConvert = 170_000_000;
ZonedDateTime end = start.plus(millisToConvert, ChronoUnit.MILLIS);
long days = ChronoUnit.DAYS.between(start, end);
System.out.format("%d days%n", days);
2 days
If you additionally want the hours, minutes and seconds:
Duration remainingTime = Duration.between(start.plusDays(days), end);
System.out.format(" - and an additional %s hours %d minutes %d seconds%n",
remainingTime.toHours(),
remainingTime.toMinutesPart(),
remainingTime.toSecondsPart());
- and an additional 0 hours 13 minutes 20 seconds
If instead you had got an endpoint, subtract your milliseconds from the endpoint using the minus method (instead of the plus method used in the above code) to get the start point.
Under no circumstances do the math yourself as in the question and in the currently accepted answer. It’s error-prone and results in code that is hard to read. And if your reader sucks at math, he or she can spend much precious developer time trying to verify that you have done it correctly. Leave the math to proven library methods, and it will be much easier for your reader to trust that your code is correct.
In case you solve a more complex task of logging execution statistics in your code:
public void logExecutionMillis(LocalDateTime start, String callerMethodName) {
LocalDateTime end = getNow();
long difference = Duration.between(start, end).toMillis();
Logger logger = LoggerFactory.getLogger(ProfilerInterceptor.class);
long millisInDay = 1000 * 60 * 60 * 24;
long millisInHour = 1000 * 60 * 60;
long millisInMinute = 1000 * 60;
long millisInSecond = 1000;
long days = difference / millisInDay;
long daysDivisionResidueMillis = difference - days * millisInDay;
long hours = daysDivisionResidueMillis / millisInHour;
long hoursDivisionResidueMillis = daysDivisionResidueMillis - hours * millisInHour;
long minutes = hoursDivisionResidueMillis / millisInMinute;
long minutesDivisionResidueMillis = hoursDivisionResidueMillis - minutes * millisInMinute;
long seconds = minutesDivisionResidueMillis / millisInSecond;
long secondsDivisionResidueMillis = minutesDivisionResidueMillis - seconds * millisInSecond;
logger.info(
"\n************************************************************************\n"
+ callerMethodName
+ "() - "
+ difference
+ " millis ("
+ days
+ " d. "
+ hours
+ " h. "
+ minutes
+ " min. "
+ seconds
+ " sec."
+ secondsDivisionResidueMillis
+ " millis).");
}
P.S. Logger can be replaced with simple System.out.println() if you like.

JodaTime Calculate total hours worked in a week

Currently I have a function which can take the start time and end time of one day, and calculate the difference between the two, giving me the hours worked in a day. What I would like to do is be able to get the hours worked for 7 days, and return a grand total, while remaining with the display format (HH:mm).
My function for a single day's total:
Period p = new Period(this.startTime[dayIndex], this.endTime[dayIndex]);
long hours = p.getHours();
long minutes = p.getMinutes();
String format = String.format("%%0%dd", 2);//Ensures that the minutes will always display as two digits.
return Long.toString(hours)+":"+String.format(format, minutes);
this.startTime[] & this.endTime[] are both arrays of DateTime objects.
Any suggestions?
You'll need something to hold a week's worth of days, and call your function once for each day.
But that means you'll want to refactor so that your calculator method doesn't format as a string, but instead returns a numeric value, so you can easily add them together.
Another simple solution:
Here is a method that receives separate the hours and minutes.The parameters are:
Start Hour
Start Minutes
End Hour
End Minutes
first, calculate the difference between hours and minutes separate:
int hours = pEndHour - pStartHour;
int minutes = ((60 - pStartMinutes) + pEndMinutes) - 60;
then, validates if the value of "minutes" variable is negative:
// If so, the "negative" value of minutes is our remnant to the next hour
if (minutes < 0) {
hours--;
minutes = 60 + minutes ;
}
Finally you can print the period of time in the hour format:
String format = String.format("%%0%dd", 2);
System.out.println( "*** " + hours + " : " + minutes);
That's all.
Solution I ended with for those interested
Period[] p=new Period[7];
long hours = 0;
long minutes =0;
for(int x=0; x<=this.daysEntered;x++)
{
p[x] = new Period(this.startTime[x], this.endTime[x]);
hours += p[x].getHours();
minutes += p[x].getMinutes();
}
hours += minutes/60;
minutes=minutes%60;
String format = String.format("%%0%dd", 2);
return Long.toString(hours)+":"+String.format(format, minutes);

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