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Convert custom date string(with am/pm) to UTC Date Time using java

I just need sample code block or suggestion to convert the following date string to utc time in format yyyy-MM-dd HH:mm:ss?
sample date string:11/23/2017 09:44am
there are similar questions like this but my test data is with am/pm.So pls dont consider this as duplicate

You could use the Java 8 time package:
String input = "11/23/2017 09:44am";
String format = "MM/dd/yyyy hh:mma";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern(format);
LocalDateTime date = LocalDateTime.parse(input, formatter);
System.out.printf("%s%n", date);
But the problem is: this throws a DateTimeParseException, because of the lowercase 'am'.
I looked up in the docs, but I couldn't see a standard way to parse lowercase 'am' or 'pm' as as meridiem designator1. You'll end up manually replacing them:
input = input.replace("AM", "am").replace("PM","pm");
As mentioned by #OleVV in the comments, you can use a DateTimeFormatterBuilder and specify that the parsing should be case-insensitive:
DateTimeFormatter formatter = new DateTimeFormatterBuilder()
.parseCaseInsensitive()
.appendPattern(format)
.toFormatter();
Then you can use this formatter as argument to the LocalDateTime.parse method.
Another answer of the aforementioned post provides a solution where you can override the AM/PM symbols with the lowercase variants.
1 Interestingly, the SimpleDateFormat does support the parsing of lowercase am/pm.

The sample code below should do the conversion correctly.
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class DateConversion {
public static void main(String[] argv) {
SimpleDateFormat formatter = new SimpleDateFormat("MM/dd/yyyy hh:mma");
SimpleDateFormat OutputFormatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String sampleDateString = "11/23/2017 09:44am";
try {
Date convertDate = formatter.parse(sampleDateString);
System.out.println(OutputFormatter.format(convertDate));
} catch (ParseException e) {
e.printStackTrace();
}
}
}
This is to declare the date string to be parsed.
SimpleDateFormat formatter = new SimpleDateFormat("MM/dd/yyyy hh:mma");
and the output date as well
SimpleDateFormat OutputFormatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

At first you need to create a SimpleDateFormat with the proper pattern. This class helps you to parse your string to java.util.Date (more info here):
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yy hh:mma");
If your original string-date is in a special timezone then you need to instruct the parser to use this timezone:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yy hh:mma", Locale.ENGLISH);
Then you need to parse the string to date:
Date d = sdf.parse("11/23/2017 09:44am");
Finnaly you have to convert the timezoned date to UTC.
Please find bellow the full code snippet:
public static void main(String[] args) throws ParseException {
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yy hh:mma", Locale.ENGLISH);
Date d = sdf.parse("11/23/2017 09:44am");
System.out.println(toUtcZonedDateTime(d));
}
public static ZonedDateTime toUtcZonedDateTime(final Date date) {
if (date == null) {
return null;
}
final ZoneId utcZone = ZoneOffset.UTC;
return ZonedDateTime.ofInstant(date.toInstant(), utcZone);
}
Output:
2017-11-23T08:44Z

SimpleDateFormat's javadoc lists all the options, including "a" for am/pm marker.
In you case, you need:
SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy hh:mm:ssa")

How to get data in java with localization?

I have table with data of date.
This is how I calcaulted the date
DateFormat dateFormat = getFormat();
date = dateFormat.parse((String) value).getTime();
if(date != null) {
cell.setValue(dateFormat.format(date));
tableViewer.update(element, null);
}
public static DateFormat getFormat() {
String systemLocale = System.getProperty("user.language"); //$NON-NLS-1$
Locale locale = new Locale(systemLocale);
DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.MEDIUM, locale);
return dateFormat;
}
The date is exist in the screen in format Month(name of the month) date, year
for example Apr 26,2014.
Now I want to get the value of the cell and to get to format of 'yyyy-mm-dd'
The value of the date is Apr 26,2014.
How I can get the result of 2014-04-26 ? also I think that the value in the UI could change according to the localization of the user
I tried
DateFormat dateFormat = getFormat();
Date parse = dateFormat.parse((String) key);
but then all the get method are deprecated and also I didn't get right result for getYear
I am not expert in the date maybe I miss something

Try this:
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
public class CustomFormattedDate {
public static void main(String[] args) {
Date date = new Date();
// if you use DD for Daypattern, you'll get the day of the year, e.g. 119 for the
// 29th April 2014, if you want 29, the day of the month, use dd
SimpleDateFormat df = new SimpleDateFormat("YYYY-dd-MMM", new Locale(System.getProperty("user.language")));
System.out.println(df.format(date));
System.out.println(getDateFormat().format(date));
}
}
Output
2014-29-Apr

how to create Date object from String value

When running through the below code I am getting an UNPARSABLE DATE EXCEPTION.
How do I fix this?
package dateWork;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class DateCreation {
/**
* #param args
*/
public static void main(String[] args) {
String startDateString = "2013-03-26";
DateFormat df = new SimpleDateFormat("yyyy/MM/dd");
Date startDate=null;
String newDateString = null;
try
{
startDate = df.parse(startDateString);
newDateString = df.format(startDate);
System.out.println(startDate);
} catch (ParseException e)
{
e.printStackTrace();
}
}
}

You used wrong dateformat for month, also you should use the same delimiter as in your date.
If you date string is of format "2013/01/03"
use the same delimiter / for the pattern "yyyy/MM/dd"
If your date string is of format "2013-01-03"
use the same delimiter '-' in your pattern "yyyy-MM-dd"
DateFormat df = new SimpleDateFormat("yyyy/mm/dd");
should be
DateFormat df = new SimpleDateFormat("yyyy/MM/dd");
From SimpleDateFormat Doc
MM---> month in an year
mm---> minutes in hour

MM instead of mm
- instead of /
ie yyyy-MM-dd as you are using - in date string

String startDateString = "2013-03-26";
DateFormat df = new SimpleDateFormat("yyyy/MM/dd");
you are using different pattern than what you are parsing.
either initialize this as DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
or this as String startDateString = "2013/03/26";
also look this article

pass same format string in constructor of SimpleDateFormat("yyyy-mm-dd")
as your string date is "2013-03-26"
if your date is "2013/03/26" use
SimpleDateFormat("yyyy/mm/dd")

Convert Unix time into readable Date in Java

What is the easiest way to do this in Java? Ideally I will be using Unix time in milliseconds as input and the function will output a String like
November 7th, 2011 at 5:00 PM

SimpleDateFormat sdf = new SimpleDateFormat("MMMM d, yyyy 'at' h:mm a");
String date = sdf.format(myTimestamp);

I wanted to convert my unix_timestamps like 1372493313 to human readable format like Jun 29 4:08.
The above answered helped me for my Android app code. A little difference was that on Android it recommends to use locale settings as well, and my original unix_timestamp was in seconds, not milliseconds, and Eclipse wanted to add try/catch block or throw exception. So my working code has to be modified a bit like this:
/**
*
* #param unix_timestamp
* #return
* #throws ParseException
*/
private String unixToDate(String unix_timestamp) throws ParseException {
long timestamp = Long.parseLong(unix_timestamp) * 1000;
SimpleDateFormat sdf = new SimpleDateFormat("MMM d H:mm", Locale.CANADA);
String date = sdf.format(timestamp);
return date.toString();
}
And here is the calling code:
String formatted_timestamp;
try {
formatted_timestamp = unixToDate(unix_timestamp); // timestamp in seconds
} catch (ParseException e) {
e.printStackTrace();
}

java.util.Date date = new java.util.Date((long) time * 1000L);
SimpleDateFormat simpleDateFormat = new SimpleDateFormat(pattern);
simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));

I have a date in(string) in dd-mon-yyyy format and I want to compare this date with system date

I have a date in(string) in dd-mon-yyyy format and I want to compare this date with system date.
eg.
I have 12-OCT-2010
and I want to compere this with system date in same format

You can use the SystemDateFormat class to parse your String, for example
final DateFormat fmt = new SimpleDateFormat("dd-MMM-yyyy");
final Date input = fmt.parse("12-OCT-2010");
if (input.before(new Date()) {
// do something
}
Note that SimpleDateFormat is not threadsafe, so needs to be wrapped in a ThreadLocal if you have more than one thread accessing your code.
You may also be interested in Joda, which provides a better date API

Use SimpleDateFormat http://download.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html
SimpleDateFormat f = new SimpleDateFormat("dd-MMM-yyyy");
String d = "12-OCT-2010";
try {
Date formatted = f.parse(d);
Date sysDate = new Date();
System.out.println(formatted);
System.out.println(sysDate);
if(formatted.before(sysDate)){
System.out.println("Formatted Date is older");
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

I would recommend using Joda Time. You can parse that String into a LocalDate object very simply, and then construct another LocalDate from the system clock. You can then compare these dates.

Using simpledateformat -
String df = "dd-MMM-yyyy";
SimpleDateFormat sdf = new SimpleDateFormat(df);
Calendar cal = Calendar.getInstance();
/* system date */
String systemdate = sdf.format(cal.getTime());
/* the date you want to compare in string format */
String yourdate = "12-Oct-2010";
Date ydate = null;
try {
ydate = sdf.parse(yourdate);
} catch (ParseException e) {
e.printStackTrace();
}
yourdate = sdf.format(ydate);
System.out.println(systemdate.equals(yourdate) ? "true" : "false");