How to convert milliseconds into hours and days?

Question

I want to get the JVM start time and uptime. So far I have done this:

public long getjvmstarttime(){
    final long uptime = ManagementFactory.getRuntimeMXBean().getStartTime();
    return uptime;
}

public long getjvmuptime(){
    final long uptime = ManagementFactory.getRuntimeMXBean().getUptime();
    return uptime;
}

But I get the time in milliseconds. How I can convert the time in days and hours. I want to display the milliseconds in this format: 3 days, 8 hours, 32 minutes. Is there amy internal Java method that can convert the milliseconds?

score 60 · Answer 1 · answered Aug 25 '12 at 20:19

60

Once you have the time in milliseconds you can use the TimeUnit enum to convert it to other time units. Converting to days will just require one call.

long days = TimeUnit.MILLISECONDS.toDays(milliseconds);

Getting the hours will involve another similar call for the total hours, then computing the left over hours after the days are subtracted out.

answered Aug 25 '12 at 20:19

Bill the Lizard

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thanks dude, you are the boss.. so much better than the accepted answer – Marko Niciforovic Mar 23 '15 at 10:59
Best answer, still the method above and pretty much all the other like .toHours(millis) return a long value, why? – Lampione Mar 06 '16 at 12:47
@VeenarM These solutions were provided on the same day, and TimeUnit has been around since Java 5. (DAYS was added to it with Java 7, which would have been a year before these posts.) – Bill the Lizard Jul 21 '17 at 02:57
O wow my bad - some reason just assumed it was part of the new DateTime components - then this is awesome and much better solution :) – VeenarM Jul 21 '17 at 10:10

score 40 · Accepted Answer · edited Aug 25 '12 at 21:20

The code below does the math you need and builds the resulting string:

private static final int SECOND = 1000;
private static final int MINUTE = 60 * SECOND;
private static final int HOUR = 60 * MINUTE;
private static final int DAY = 24 * HOUR;

// TODO: this is the value in ms
long ms = 10304004543l;
StringBuffer text = new StringBuffer("");
if (ms > DAY) {
  text.append(ms / DAY).append(" days ");
  ms %= DAY;
}
if (ms > HOUR) {
  text.append(ms / HOUR).append(" hours ");
  ms %= HOUR;
}
if (ms > MINUTE) {
  text.append(ms / MINUTE).append(" minutes ");
  ms %= MINUTE;
}
if (ms > SECOND) {
  text.append(ms / SECOND).append(" seconds ");
  ms %= SECOND;
}
text.append(ms + " ms");
System.out.println(text.toString());

Your if statements should be checking if ms is greater or equal to DAY/MINUTE/HOUR/SECOND. For instance if ms=1000, it will show as 0 seconds. — MrK, Jan 29 '17 at 02:48

score 2 · Answer 3 · answered Aug 25 '12 at 20:20

2

Take a look at Pretty Time. It's a library for generating human reabable time strings from timestamps like milliseconds.

answered Aug 25 '12 at 20:20

Jon Lin

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score 1 · Answer 4 · edited Apr 29 '21 at 11:50

There below code cleanly does the job

package com.company;

import java.util.Scanner;
import java.util.concurrent.TimeUnit;

public class Main {

    public static void main(String[] args) {
        final long milliseconds;
        Scanner in = new Scanner(System.in);

        System.out.println("Enter time in milliseconds: ");
        milliseconds = in.nextLong();

        final long seconds = TimeUnit.MILLISECONDS.toSeconds(milliseconds);

        final long minute = TimeUnit.MILLISECONDS.toMinutes(milliseconds);

        final long hours = TimeUnit.MILLISECONDS.toHours(milliseconds);

        final long days = TimeUnit.MILLISECONDS.toDays(milliseconds);

        if(milliseconds < 1000){
            System.out.println(days +"d:" +hours+"h:" +minute+"m:" +seconds +"s:" +milliseconds +"ms");
        }
        else{
            System.out.println(days +"d:" +hours % 24 +"h:" +minute % 60 +"m:" +seconds % 60 +"s");
        }
    }
}

Sample output

Enter time in milliseconds: 12000000

0d:3h:20m:0s

How to convert milliseconds into hours and days?

4 Answers4

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