How can I parse UTC date/time (String) into something more readable?

Question

I have a String of a date and time like this: 2011-04-15T20:08:18Z. I don\'t know much about date/time formats, but I think, and correct me if I\'m wrong, that\

Answer 1

Already has lot of answer but just wanted to update with java 8 in case any one faced issues while parsing string date.

Generally we face two problems with dates

1. Parsing String to Date
2. Display Date in desired string format

DateTimeFormatter class in Java 8 can be used for both of these purpose. Below methods try to provide solution to these issues.

Method 1: Convert your UTC string to Instant. Using Instant you can create Date for any time-zone by providing time-zone string and use DateTimeFormatter to format date for display as you wish.

String dateString = "2016-07-13T18:08:50.118Z";
String tz = "America/Mexico_City";
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("MMM d yyyy hh:mm a");
ZoneId zoneId = ZoneId.of(tz);

Instant instant = Instant.parse(dateString);

ZonedDateTime dateTimeInTz =ZonedDateTime.ofInstant(instant, zoneId);

System.out.println(dateTimeInTz.format(dtf));

Method 2:

Use DateTimeFormatter built in constants e.g ISO_INSTANT to parse string to LocalDate. ISO_INSTANT can parse dates of pattern

yyyy-MM-dd'T'HH:mm:ssX e.g '2011-12-03T10:15:30Z'

LocalDate parsedDate
  = LocalDate.parse(dateString, DateTimeFormatter.ISO_INSTANT);

DateTimeFormatter displayFormatter = DateTimeFormatter.ofPattern("yyyy MM dd");
System.out.println(parsedDate.format(displayFormatter));

Method 3:

If your date string has much precision of time e.g it captures fraction of seconds as well as in this case 2016-07-13T18:08:50.118Z then method 1 will work but method 2 will not work. If you try to parse it will throw DateTimeException Since ISO_INSTANT formatter will not be able to parse fraction of seconds as you can see from its pattern. In this case you will have to create a custom DateTimeFormatter by providing date pattern as below.

LocalDate localDate 
= LocalDate.parse(date, DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSX"));

Taken from a blog link written by me.

Answer 2

You have to give the following format:

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
Date parse = simpleDateFormat.parse( "2011-04-15T20:08:18Z" );

Answer 3

For all the older versions of JDK (6 down) it may be useful.

Getting rid of trailing 'Z' and replacing it literally with 'UTC' timezone display name - then parsing the whole string using proper simple date formatter.

String timeZuluVal = "2011-04-15T20:08:18Z";
timeZuluVal = timeZuluVal.substring( 0, timeZuluVal.length() - 2 ); // strip 'Z';
timeZuluVal += " " + TimeZone.getTimeZone( "UTC" ).getDisplayName();
DateFormat simpleDateFormat = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ss zzzz" );
Date dateVal = simpleDateFormat.parse( timeZuluVal );

Answer 4

The Java 7 version of SimpleDateFormat supports ISO-8601 time zones using the uppercase letter X.

String string = "2011-04-15T20:08:18Z";
DateFormat iso8601 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
Date date = iso8601.parse(string);

If you're stuck with Java 6 or earlier, the answer recommending JodaTime is a safe bet.

Answer 5

the pattern in @khmarbaise answer worked for me, here's the utility method I extracted (note that the Z is omitted from the pattern string):

/**
 * Converts an ISO-8601 formatted UTC timestamp.
 *
 * @return The parsed {@link Date}, or null.
 */
@Nullable
public static Date fromIsoUtcString(String isoUtcString) {
    DateFormat isoUtcFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss", Locale.getDefault());
    isoUtcFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
    try {
        return isoUtcFormat.parse(isoUtcString);
    } catch (ParseException e) {
        e.printStackTrace();
        return null;
    }
}

Answer 6

What you have is an ISO-8601 date format which means you can just use SimpleDateFormat

DateFormat m_ISO8601Local = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");

And then you can just use SimpleDateFormat.parse(). Also, here is a blog post with some examples that might help.

Update:

Read the comments below before using this solution.