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How to build stopwatch with hundreth of a second precision?

I'm trying to build a stopwatch with hundreth of second precision. I have this code that runs every 10 milliseconds but I am having trouble converting it to a 0(min):0(sec):00 format.
timer.post(new Runnable() {
#Override
public void run() {
time += 1;
txtView.setText(convertTimeToText(time));
timer.postDelayed(this, 10);
}
});
private String convertTimeToText(int time) {
String convertedTime = time / 6000 + ":" + (time / 100) % 60
+ ":" + (time / 10) % 10 + time % 10;
return convertedTime;
}
I need help with the convertTimeToText(int time){} that formats time.
EDIT:
Thanks to Ole V.V. and WJS for the formatting answer and how to fix the delay I was having, this is the code I came up with if anybody needs it, so far it works well, maybe using System.nanoTime() will get you more accurate results but for my use its fine.
public void start(){
final long timeMillisWhenStarted = System.currentTimeMillis();
if(!isRunning){
isRunning = true;
timer.post(new Runnable() {
#Override
public void run() {
long millisNow = System.currentTimeMillis();
long time = millisNow - timeMillisWhenStarted;
yourtxtView.setText(convertTimeToText(time));
timer.postDelayed(this, 10);
}
});
}
}
private String convertTimeToText(long time){
long hundredths = time / 10;
long sec = hundredths / 100;
long min = sec / 60;
return String.format("%02d:%02d.%02d", min % 60, sec % 60, hundredths % 100);
}

See if this helps. The remainders weren't being computed correctly.
For 12340 hundreds of seconds that would be 123.40 seconds
so 12340 / 6000 = 2 for minutes
12340 % 6000 gets what's left which is 340
so 340 /100 = 3 seconds
leaving 340 % 100= 40 hundredths
public static void main(String[] args) {
// n = 16 mins 4 seconds and 99 hundredths
int n = (16 * 6000) + (4 * 100) + 99;
System.out.println(convertTimeToText(n));
}
private static String convertTimeToText(int time) {
int mins = time / 6000;
time %= 6000; // get remaining hundredths
int seconds = time / 100;
int hundredths = time %= 100; // get remaining hundredths
// format the time. The leading 0's mean to pad single
// digits on the left with 0. The 2 is a field width
return String.format("%02d:%02d:%02d", mins, seconds,
hundredths);
}
This prints
16:04:99

Use the standard library
Your timer isn’t accurate. Your observed delay comes from there. Read the time off some clock each time rather than adding 1/100 second. Use for example System.currentTimeMillis(), System.nanoTime() or Instant.now(). Keep the reading from when your stopwatch was started and subtract for getting the current stopwatch value.
Should performing a system call 100 times per second be too expensive (which I don’t expect), do it for example for every 30 ticks to adjust your stopwatch back to the correct time.
Next if you are using Java 9 or higher, use the Duration class for converting from the the time (whether in milliseconds or nanoseconds) to minutes and seconds. If you do the conversion by hand as you tried, it’s error-prone and hard to read, which — I believe — was one reason for your question.
For example:
long millisNow = System.currentTimeMillis();
Duration time = Duration.ofMillis(millisNow - timeMillisWhenStarted);
String convertedTime = String.format("%d:%02d.%02d",
time.toMinutes(), time.toSecondsPart(), time.toMillisPart() / 10);

get duration in digital form

I have a music player which has a function called getcurrentposn which returns the current position in milliseconds, I want to display the result in the TextView in this form mm:ss.
I made a getAsTime function which have returns the time in my app in the digital form i.e. mm:ss.
This is what I tried:
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
long seconds = minutes * 60;
if(millis!=0) {
long totalSeconds = TimeUnit.MILLISECONDS.toSeconds(millis);
if(seconds!=0)
seconds = totalSeconds / seconds;
else seconds=totalSeconds;
}
if(minutes<10 && seconds <10)
return "0"+minutes + ":" +"0"+ seconds;
if(minutes<10 && seconds>=10)
return "0"+minutes + ":" + seconds;
if(minutes>=10 && seconds<10)
return minutes + ":" +"0"+ seconds;
return minutes+":"+seconds;
}
But the problem with that it is doesn't seem to work correctly.
Is there any inbuilt function to do so? if not how do I achieve it the correct way?
Example: 01:00
02:09

First convert the milliseconds to seconds:
int t = millis / 1000;
Then convert those to minutes and seconds
int minutes = t / 60; //since both are ints, you get an int
int seconds = t % 60;
Then return a string formatted like you want it with added padding
return String.format("%02d:%02d", minutes, seconds);

Java String Time Formatting

Is there a way to do this without the if ( hours > 0 ) ? I feel like there must be a way to indicate a conditional display for the digit, but I couldn't find it in the javadocs or with google.
public String getLengthDisplay () {
int hours = getLength() / 3600;
int minutes = ( getLength() % 3600 ) / 60;
int seconds = getLength() % 60;
if ( hours > 0 ) {
return String.format ( "%d:%02d:%02d", hours, minutes, seconds );
} else {
return String.format ( "%d:%02d", minutes, seconds );
}
}
Thanks!

I don't think the code will be flexible without the hour > 0 condition.
Trimming is also a good option.
/**
* This method is used to get the Execution Time
* by calculating the difference between StartTime and EndTime
*
* #param StartTime Execution Start Time
* #param EndTime Execution End Time
* #return Total Execution Time
*/
private static String ExecutionTime(String StartTime, String EndTime){
LocalTime fromDateTime = LocalTime.parse(StartTime);
LocalTime toDateTime = LocalTime.parse(EndTime);
LocalTime tempDateTime = LocalTime.from( fromDateTime );
long hours = tempDateTime.until( toDateTime, ChronoUnit.HOURS);
tempDateTime = tempDateTime.plusHours( hours );
long minutes = tempDateTime.until( toDateTime, ChronoUnit.MINUTES);
tempDateTime = tempDateTime.plusMinutes( minutes );
long seconds = tempDateTime.until( toDateTime, ChronoUnit.SECONDS);
if(hours > 0){
return hours + "h " +minutes + "min " + seconds + "s";
}else{
return minutes + "min " + seconds + "s";
}
}
Check the above code, which return Hour Minute Second format, you can add minute condition also if needed.

There's no way with format(), but just trim leading zeros:
return String.format("%d:%02d:%02d", hours, minutes, seconds)
.replaceAll("^0:(00:)?", "");
This code also trims the minutes if both hour and minute are zero. If you always want the minutes, delete (00:)? from this code.

TimeUtil package in java [duplicate]

I want to record the time using System.currentTimeMillis() when a user begins something in my program. When he finishes, I will subtract the current System.currentTimeMillis() from the start variable, and I want to show them the time elapsed using a human readable format such as "XX hours, XX mins, XX seconds" or even "XX mins, XX seconds" because its not likely to take someone an hour.
What's the best way to do this?

Use the java.util.concurrent.TimeUnit class:
String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes(millis),
TimeUnit.MILLISECONDS.toSeconds(millis) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);
Note: TimeUnit is part of the Java 1.5 specification, but toMinutes was added as of Java 1.6.
To add a leading zero for values 0-9, just do:
String.format("%02d min, %02d sec",
TimeUnit.MILLISECONDS.toMinutes(millis),
TimeUnit.MILLISECONDS.toSeconds(millis) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millis))
);
If TimeUnit or toMinutes are unsupported (such as on Android before API version 9), use the following equations:
int seconds = (int) (milliseconds / 1000) % 60 ;
int minutes = (int) ((milliseconds / (1000*60)) % 60);
int hours = (int) ((milliseconds / (1000*60*60)) % 24);
//etc...

Based on #siddhadev's answer, I wrote a function which converts milliseconds to a formatted string:
/**
* Convert a millisecond duration to a string format
*
* #param millis A duration to convert to a string form
* #return A string of the form "X Days Y Hours Z Minutes A Seconds".
*/
public static String getDurationBreakdown(long millis) {
if(millis < 0) {
throw new IllegalArgumentException("Duration must be greater than zero!");
}
long days = TimeUnit.MILLISECONDS.toDays(millis);
millis -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(minutes);
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis);
StringBuilder sb = new StringBuilder(64);
sb.append(days);
sb.append(" Days ");
sb.append(hours);
sb.append(" Hours ");
sb.append(minutes);
sb.append(" Minutes ");
sb.append(seconds);
sb.append(" Seconds");
return(sb.toString());
}

long time = 1536259;
return (new SimpleDateFormat("mm:ss:SSS")).format(new Date(time));
Prints:
25:36:259

Using the java.time package in Java 8:
Instant start = Instant.now();
Thread.sleep(63553);
Instant end = Instant.now();
System.out.println(Duration.between(start, end));
Output is in ISO 8601 Duration format: PT1M3.553S (1 minute and 3.553 seconds).

Uhm... how many milliseconds are in a second? And in a minute? Division is not that hard.
int seconds = (int) ((milliseconds / 1000) % 60);
int minutes = (int) ((milliseconds / 1000) / 60);
Continue like that for hours, days, weeks, months, year, decades, whatever.

I would not pull in the extra dependency just for that (division is not that hard, after all), but if you are using Commons Lang anyway, there are the DurationFormatUtils.
Example Usage (adapted from here):
import org.apache.commons.lang3.time.DurationFormatUtils
public String getAge(long value) {
long currentTime = System.currentTimeMillis();
long age = currentTime - value;
String ageString = DurationFormatUtils.formatDuration(age, "d") + "d";
if ("0d".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "H") + "h";
if ("0h".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "m") + "m";
if ("0m".equals(ageString)) {
ageString = DurationFormatUtils.formatDuration(age, "s") + "s";
if ("0s".equals(ageString)) {
ageString = age + "ms";
}
}
}
}
return ageString;
}
Example:
long lastTime = System.currentTimeMillis() - 2000;
System.out.println("Elapsed time: " + getAge(lastTime));
//Output: 2s
Note: To get millis from two LocalDateTime objects you can use:
long age = ChronoUnit.MILLIS.between(initTime, LocalDateTime.now())

Either hand divisions, or use the SimpleDateFormat API.
long start = System.currentTimeMillis();
// do your work...
long elapsed = System.currentTimeMillis() - start;
DateFormat df = new SimpleDateFormat("HH 'hours', mm 'mins,' ss 'seconds'");
df.setTimeZone(TimeZone.getTimeZone("GMT+0"));
System.out.println(df.format(new Date(elapsed)));
Edit by Bombe: It has been shown in the comments that this approach only works for smaller durations (i.e. less than a day).

Just to add more info
if you want to format like: HH:mm:ss
0 <= HH <= infinite
0 <= mm < 60
0 <= ss < 60
use this:
int h = (int) ((startTimeInMillis / 1000) / 3600);
int m = (int) (((startTimeInMillis / 1000) / 60) % 60);
int s = (int) ((startTimeInMillis / 1000) % 60);
I just had this issue now and figured this out

Shortest solution:
Here's probably the shortest which also deals with time zones.
System.out.printf("%tT", millis-TimeZone.getDefault().getRawOffset());
Which outputs for example:
00:18:32
Explanation:
%tT is the time formatted for the 24-hour clock as %tH:%tM:%tS.
%tT also accepts longs as input, so no need to create a Date. printf() will simply print the time specified in milliseconds, but in the current time zone therefore we have to subtract the raw offset of the current time zone so that 0 milliseconds will be 0 hours and not the time offset value of the current time zone.
Note #1: If you need the result as a String, you can get it like this:
String t = String.format("%tT", millis-TimeZone.getDefault().getRawOffset());
Note #2: This only gives correct result if millis is less than a day because the day part is not included in the output.

I think the best way is:
String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toSeconds(length)/60,
TimeUnit.MILLISECONDS.toSeconds(length) % 60 );

Revisiting #brent-nash contribution, we could use modulus function instead of subtractions and use String.format method for the result string:
/**
* Convert a millisecond duration to a string format
*
* #param millis A duration to convert to a string form
* #return A string of the form "X Days Y Hours Z Minutes A Seconds B Milliseconds".
*/
public static String getDurationBreakdown(long millis) {
if (millis < 0) {
throw new IllegalArgumentException("Duration must be greater than zero!");
}
long days = TimeUnit.MILLISECONDS.toDays(millis);
long hours = TimeUnit.MILLISECONDS.toHours(millis) % 24;
long minutes = TimeUnit.MILLISECONDS.toMinutes(millis) % 60;
long seconds = TimeUnit.MILLISECONDS.toSeconds(millis) % 60;
long milliseconds = millis % 1000;
return String.format("%d Days %d Hours %d Minutes %d Seconds %d Milliseconds",
days, hours, minutes, seconds, milliseconds);
}

Joda-Time
Using Joda-Time:
DateTime startTime = new DateTime();
// do something
DateTime endTime = new DateTime();
Duration duration = new Duration(startTime, endTime);
Period period = duration.toPeriod().normalizedStandard(PeriodType.time());
System.out.println(PeriodFormat.getDefault().print(period));

For those who looking for Kotlin code:
fun converter(millis: Long): String =
String.format(
"%02d : %02d : %02d",
TimeUnit.MILLISECONDS.toHours(millis),
TimeUnit.MILLISECONDS.toMinutes(millis) - TimeUnit.HOURS.toMinutes(
TimeUnit.MILLISECONDS.toHours(millis)
),
TimeUnit.MILLISECONDS.toSeconds(millis) - TimeUnit.MINUTES.toSeconds(
TimeUnit.MILLISECONDS.toMinutes(millis)
)
)
Sample output: 09 : 10 : 26

My simple calculation:
String millisecToTime(int millisec) {
int sec = millisec/1000;
int second = sec % 60;
int minute = sec / 60;
if (minute >= 60) {
int hour = minute / 60;
minute %= 60;
return hour + ":" + (minute < 10 ? "0" + minute : minute) + ":" + (second < 10 ? "0" + second : second);
}
return minute + ":" + (second < 10 ? "0" + second : second);
}
Happy coding :)

Firstly, System.currentTimeMillis() and Instant.now() are not ideal for timing. They both report the wall-clock time, which the computer doesn't know precisely, and which can move erratically, including going backwards if for example the NTP daemon corrects the system time. If your timing happens on a single machine then you should instead use System.nanoTime().
Secondly, from Java 8 onwards java.time.Duration is the best way to represent a duration:
long start = System.nanoTime();
// do things...
long end = System.nanoTime();
Duration duration = Duration.ofNanos(end - start);
System.out.println(duration); // Prints "PT18M19.511627776S"
System.out.printf("%d Hours %d Minutes %d Seconds%n",
duration.toHours(), duration.toMinutes() % 60, duration.getSeconds() % 60);
// prints "0 Hours 18 Minutes 19 Seconds"

for Android below API 9
(String.format("%d hr %d min, %d sec", millis/(1000*60*60), (millis%(1000*60*60))/(1000*60), ((millis%(1000*60*60))%(1000*60))/1000))

For small times, less than an hour, I prefer:
long millis = ...
System.out.printf("%1$TM:%1$TS", millis);
// or
String str = String.format("%1$TM:%1$TS", millis);
for longer intervalls:
private static final long HOUR = TimeUnit.HOURS.toMillis(1);
...
if (millis < HOUR) {
System.out.printf("%1$TM:%1$TS%n", millis);
} else {
System.out.printf("%d:%2$TM:%2$TS%n", millis / HOUR, millis % HOUR);
}

Here is an answer based on Brent Nash answer, Hope that helps !
public static String getDurationBreakdown(long millis)
{
String[] units = {" Days ", " Hours ", " Minutes ", " Seconds "};
Long[] values = new Long[units.length];
if(millis < 0)
{
throw new IllegalArgumentException("Duration must be greater than zero!");
}
values[0] = TimeUnit.MILLISECONDS.toDays(millis);
millis -= TimeUnit.DAYS.toMillis(values[0]);
values[1] = TimeUnit.MILLISECONDS.toHours(millis);
millis -= TimeUnit.HOURS.toMillis(values[1]);
values[2] = TimeUnit.MILLISECONDS.toMinutes(millis);
millis -= TimeUnit.MINUTES.toMillis(values[2]);
values[3] = TimeUnit.MILLISECONDS.toSeconds(millis);
StringBuilder sb = new StringBuilder(64);
boolean startPrinting = false;
for(int i = 0; i < units.length; i++){
if( !startPrinting && values[i] != 0)
startPrinting = true;
if(startPrinting){
sb.append(values[i]);
sb.append(units[i]);
}
}
return(sb.toString());
}

long startTime = System.currentTimeMillis();
// do your work...
long endTime=System.currentTimeMillis();
long diff=endTime-startTime;
long hours=TimeUnit.MILLISECONDS.toHours(diff);
diff=diff-(hours*60*60*1000);
long min=TimeUnit.MILLISECONDS.toMinutes(diff);
diff=diff-(min*60*1000);
long seconds=TimeUnit.MILLISECONDS.toSeconds(diff);
//hour, min and seconds variables contains the time elapsed on your work

This is easier in Java 9:
Duration elapsedTime = Duration.ofMillis(millisDiff );
String humanReadableElapsedTime = String.format(
"%d hours, %d mins, %d seconds",
elapsedTime.toHours(),
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
This produces a string like 0 hours, 39 mins, 9 seconds.
If you want to round to whole seconds before formatting:
elapsedTime = elapsedTime.plusMillis(500).truncatedTo(ChronoUnit.SECONDS);
To leave out the hours if they are 0:
long hours = elapsedTime.toHours();
String humanReadableElapsedTime;
if (hours == 0) {
humanReadableElapsedTime = String.format(
"%d mins, %d seconds",
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
} else {
humanReadableElapsedTime = String.format(
"%d hours, %d mins, %d seconds",
hours,
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
}
Now we can have for example 39 mins, 9 seconds.
To print minutes and seconds with leading zero to make them always two digits, just insert 02 into the relevant format specifiers, thus:
String humanReadableElapsedTime = String.format(
"%d hours, %02d mins, %02d seconds",
elapsedTime.toHours(),
elapsedTime.toMinutesPart(),
elapsedTime.toSecondsPart());
Now we can have for example 0 hours, 39 mins, 09 seconds.

for correct strings ("1hour, 3sec", "3 min" but not "0 hour, 0 min, 3 sec") i write this code:
int seconds = (int)(millis / 1000) % 60 ;
int minutes = (int)((millis / (1000*60)) % 60);
int hours = (int)((millis / (1000*60*60)) % 24);
int days = (int)((millis / (1000*60*60*24)) % 365);
int years = (int)(millis / 1000*60*60*24*365);
ArrayList<String> timeArray = new ArrayList<String>();
if(years > 0)
timeArray.add(String.valueOf(years) + "y");
if(days > 0)
timeArray.add(String.valueOf(days) + "d");
if(hours>0)
timeArray.add(String.valueOf(hours) + "h");
if(minutes>0)
timeArray.add(String.valueOf(minutes) + "min");
if(seconds>0)
timeArray.add(String.valueOf(seconds) + "sec");
String time = "";
for (int i = 0; i < timeArray.size(); i++)
{
time = time + timeArray.get(i);
if (i != timeArray.size() - 1)
time = time + ", ";
}
if (time == "")
time = "0 sec";

If you know the time difference would be less than an hour, then you can use following code:
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
c2.add(Calendar.MINUTE, 51);
long diff = c2.getTimeInMillis() - c1.getTimeInMillis();
c2.set(Calendar.MINUTE, 0);
c2.set(Calendar.HOUR, 0);
c2.set(Calendar.SECOND, 0);
DateFormat df = new SimpleDateFormat("mm:ss");
long diff1 = c2.getTimeInMillis() + diff;
System.out.println(df.format(new Date(diff1)));
It will result to: 51:00

This answer is similar to some answers above. However, I feel that it would be beneficial because, unlike other answers, this will remove any extra commas or whitespace and handles abbreviation.
/**
* Converts milliseconds to "x days, x hours, x mins, x secs"
*
* #param millis
* The milliseconds
* #param longFormat
* {#code true} to use "seconds" and "minutes" instead of "secs" and "mins"
* #return A string representing how long in days/hours/minutes/seconds millis is.
*/
public static String millisToString(long millis, boolean longFormat) {
if (millis < 1000) {
return String.format("0 %s", longFormat ? "seconds" : "secs");
}
String[] units = {
"day", "hour", longFormat ? "minute" : "min", longFormat ? "second" : "sec"
};
long[] times = new long[4];
times[0] = TimeUnit.DAYS.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[0], TimeUnit.DAYS);
times[1] = TimeUnit.HOURS.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[1], TimeUnit.HOURS);
times[2] = TimeUnit.MINUTES.convert(millis, TimeUnit.MILLISECONDS);
millis -= TimeUnit.MILLISECONDS.convert(times[2], TimeUnit.MINUTES);
times[3] = TimeUnit.SECONDS.convert(millis, TimeUnit.MILLISECONDS);
StringBuilder s = new StringBuilder();
for (int i = 0; i < 4; i++) {
if (times[i] > 0) {
s.append(String.format("%d %s%s, ", times[i], units[i], times[i] == 1 ? "" : "s"));
}
}
return s.toString().substring(0, s.length() - 2);
}
/**
* Converts milliseconds to "x days, x hours, x mins, x secs"
*
* #param millis
* The milliseconds
* #return A string representing how long in days/hours/mins/secs millis is.
*/
public static String millisToString(long millis) {
return millisToString(millis, false);
}

There is a problem. When milliseconds is 59999, actually it is 1 minute but it will be computed as 59 seconds and 999 milliseconds is lost.
Here is a modified version based on previous answers, which can solve this loss:
public static String formatTime(long millis) {
long seconds = Math.round((double) millis / 1000);
long hours = TimeUnit.SECONDS.toHours(seconds);
if (hours > 0)
seconds -= TimeUnit.HOURS.toSeconds(hours);
long minutes = seconds > 0 ? TimeUnit.SECONDS.toMinutes(seconds) : 0;
if (minutes > 0)
seconds -= TimeUnit.MINUTES.toSeconds(minutes);
return hours > 0 ? String.format("%02d:%02d:%02d", hours, minutes, seconds) : String.format("%02d:%02d", minutes, seconds);
}

I have covered this in another answer but you can do:
public static Map<TimeUnit,Long> computeDiff(Date date1, Date date2) {
long diffInMillies = date2.getTime() - date1.getTime();
List<TimeUnit> units = new ArrayList<TimeUnit>(EnumSet.allOf(TimeUnit.class));
Collections.reverse(units);
Map<TimeUnit,Long> result = new LinkedHashMap<TimeUnit,Long>();
long milliesRest = diffInMillies;
for ( TimeUnit unit : units ) {
long diff = unit.convert(milliesRest,TimeUnit.MILLISECONDS);
long diffInMilliesForUnit = unit.toMillis(diff);
milliesRest = milliesRest - diffInMilliesForUnit;
result.put(unit,diff);
}
return result;
}
The output is something like Map:{DAYS=1, HOURS=3, MINUTES=46, SECONDS=40, MILLISECONDS=0, MICROSECONDS=0, NANOSECONDS=0}, with the units ordered.
It's up to you to figure out how to internationalize this data according to the target locale.

DurationFormatUtils.formatDurationHMS(long)

I modified #MyKuLLSKI 's answer and added plurlization support. I took out seconds because I didn't need them, though feel free to re-add it if you need it.
public static String intervalToHumanReadableTime(int intervalMins) {
if(intervalMins <= 0) {
return "0";
} else {
long intervalMs = intervalMins * 60 * 1000;
long days = TimeUnit.MILLISECONDS.toDays(intervalMs);
intervalMs -= TimeUnit.DAYS.toMillis(days);
long hours = TimeUnit.MILLISECONDS.toHours(intervalMs);
intervalMs -= TimeUnit.HOURS.toMillis(hours);
long minutes = TimeUnit.MILLISECONDS.toMinutes(intervalMs);
StringBuilder sb = new StringBuilder(12);
if (days >= 1) {
sb.append(days).append(" day").append(pluralize(days)).append(", ");
}
if (hours >= 1) {
sb.append(hours).append(" hour").append(pluralize(hours)).append(", ");
}
if (minutes >= 1) {
sb.append(minutes).append(" minute").append(pluralize(minutes));
} else {
sb.delete(sb.length()-2, sb.length()-1);
}
return(sb.toString());
}
}
public static String pluralize(long val) {
return (Math.round(val) > 1 ? "s" : "");
}

Use java.util.concurrent.TimeUnit, and use this simple method:
private static long timeDiff(Date date, Date date2, TimeUnit unit) {
long milliDiff=date2.getTime()-date.getTime();
long unitDiff = unit.convert(milliDiff, TimeUnit.MILLISECONDS);
return unitDiff;
}
For example:
SimpleDateFormat sdf = new SimpleDateFormat("yy/MM/dd HH:mm:ss");
Date firstDate = sdf.parse("06/24/2017 04:30:00");
Date secondDate = sdf.parse("07/24/2017 05:00:15");
Date thirdDate = sdf.parse("06/24/2017 06:00:15");
System.out.println("days difference: "+timeDiff(firstDate,secondDate,TimeUnit.DAYS));
System.out.println("hours difference: "+timeDiff(firstDate,thirdDate,TimeUnit.HOURS));
System.out.println("minutes difference: "+timeDiff(firstDate,thirdDate,TimeUnit.MINUTES));
System.out.println("seconds difference: "+timeDiff(firstDate,thirdDate,TimeUnit.SECONDS));

This topic has been well covered, I just wanted to share my functions perhaps you can make use of these rather than importing an entire library.
public long getSeconds(ms) {
return (ms/1000%60);
}
public long getMinutes(ms) {
return (ms/(1000*60)%60);
}
public long getHours(ms) {
return ((ms/(1000*60*60))%24);
}

Convert int to time Java

I have an int counter that starts at 600 and in a Runnable and is increased by 1.
600 represents 6 am, and 2400 represents midnight.
This int is compared to a int received from an API in the same format.
I need to compare them both; however, the problem is my int has 100 mins in an hour at the moment, so as time goes on it gets more and more out of time.
Is there a way to convert the int counter to a time format? (The Java format of 18000000 = 6am doesn't work)
Cheers Phil

Dave Newton is right by saying its just math. Your integer time is composed by two components, hours and minutes (which is easy to read but difficult to calculate).
int time = 600;
int hours = time / 100;
int minutes = (time - hours * 100) % 60;
So you can't just increment your time (time++), because you end up with a houndred minutes per hour as you wrote. Use this method instead:
int incrementTime(int time) {
time++;
int hours = time / 100;
int minutes = (time - hours * 100) % 60;
if (minutes == 0) hours++;
return hours * 100 + minutes;
}
You can try it out:
time = 600;
for (int i=0; i < 120; i++) {
time = incrementTime(time);
System.out.println(time);
}

If you do really need to transform your 0 --> 2400 to a "time format", you might use:
hour = uTime/100
uMinutes = uTime - hour*100
normalMinutes = (60*uMinutes)/100
Then go about changing to "long" and milliseconds for use elsewhere.

Java already has a way to convert a datetime to a number and vice versa.
//Get integer representation of time
Calendar rightNow = Calendar.getInstance();
long integerRepresentation = rightNow.getTimeInMillis();
//Set time to integer reprsentation
Calendar calendar2 = Calendar.getInstance();
calendar2.setTimeInMillis(integerRepresentation);