How to convert minutes to Hours and minutes (hh:mm) in java

If your time is in a variable called t

int hours = t / 60; //since both are ints, you get an int
int minutes = t % 60;
System.out.printf("%d:%02d", hours, minutes);

It couldn't get easier


tl;dr

Duration.ofMinutes( 260L )
        .toString()

PT4H20M

… or …

LocalTime.MIN.plus( 
    Duration.ofMinutes( 260L ) 
).toString()

04:20

Duration

The java.time classes include a pair of classes to represent spans of time. The Duration class is for hours-minutes-seconds, and Period is for years-months-days.

Duration d = Duration.ofMinutes( 260L );

Duration parts

Access each part of the Duration by calling to…Part. These methods were added in Java 9 and later.

long days = d.toDaysPart() ;
int hours = d.toHoursPart() ;
int minutes = d.toMinutesPart() ;
int seconds = d.toSecondsPart() ;
int nanos = d.toNanosPart() ;

You can then assemble your own string from those parts.

ISO 8601

The ISO 8601 standard defines textual formats for date-time values. For spans of time unattached to the timeline, the standard format is PnYnMnDTnHnMnS. The P marks the beginning, and the T separates the years-month-days from the hours-minutes-seconds. So an hour and a half is PT1H30M.

The java.time classes use ISO 8601 formats by default for parsing and generating strings. The Duration and Period classes use this particular standard format. So simply call toString.

String output = d.toString();

PT4H20M

For alternate formatting, build your own String in Java 9 and later (not in Java 8) with the Duration::to…Part methods. Or see this Answer for using regex to manipulate the ISO 8601 formatted string.

LocalTime

I strongly suggest using the standard ISO 8601 format instead of the extremely ambiguous and confusing clock format of 04:20. But if you insist, you can get this effect by hacking with the LocalTime class. This works if your duration is not over 24 hours.

LocalTime hackUseOfClockAsDuration = LocalTime.MIN.plus( d );
String output = hackUseOfClockAsDuration.toString();

04:20

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

  • Java SE 8 and SE 9 and later
    • Built-in.
    • Part of the standard Java API with a bundled implementation.
    • Java 9 adds some minor features and fixes.
  • Java SE 6 and SE 7
    • Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
  • Android
    • The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
    • See How to use ThreeTenABP….

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.


You can also use the TimeUnit class. You could define 

private static final String FORMAT = "%02d:%02d:%02d";
can have a method like:

public static String parseTime(long milliseconds) {
      return String.format(FORMAT,
              TimeUnit.MILLISECONDS.toHours(milliseconds),
              TimeUnit.MILLISECONDS.toMinutes(milliseconds) - TimeUnit.HOURS.toMinutes(
              TimeUnit.MILLISECONDS.toHours(milliseconds)),
              TimeUnit.MILLISECONDS.toSeconds(milliseconds) - TimeUnit.MINUTES.toSeconds(
              TimeUnit.MILLISECONDS.toMinutes(milliseconds)));
   }

Tags:

Java

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