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How should the moveForward(lostTime) give the correct output when the hour and minute variables go below zero?

I knew the method of delaying by minutes, for instance, from 22:50 to 2:10. I inserted 200 in the parameter of delay method, I am concerned that the method of moving the time forward is not working as I attempted by setting the time 1:20 and moving 100 minutes (1 hour and 40 minutes) forward to 23:40. As I tried to run the code, the output displayed 1:40 after moving the time forward. Which line was wrong in the method of moveForward(int lostMinute)?
class Time
{
private int hour; // between 0 - 23
private int minute; // between 0 - 59
public Time()
{
this(0, 0);
}
public Time(int hr, int min)
{
hour = (hr >= 0 && hr < 24) ? hr : 0;
minute = (min >= 0 && min < 60) ? min : 0;
}
public int getHour()
{
return hour;
}
public int getMinute()
{
return minute;
}
public void setHour(int hour)
{
this.hour = (hour >= 0 && hour < 24) ? hour : 0;
public void setMinute(int minute)
{
this.minute = (minute >= 0 && minute < 60) ? minute : 0;
}
public String toString()
{
return String.format("%02d:%02d", hour, minute);
}
public void delay(int newMinute)
{
minute = minute + newMinute;
if(minute >= 60)
{
// (minute / 60) is an integer division and truncates the remainder, which refers to (minute % 60)
hour = hour + (minute / 60);
minute = minute % 60;
if(hour >= 24)
{
hour = hour % 24;
}
}
}
public void moveForward(int lostMinute)
{
if(minute < lostMinute)
{
hour = hour - ((60 + minute) / 60);
minute = (minute + 60) % 60;
if(hour < 0)
{
hour = (24 + hour) % 24;
}
}
else
{
minute = minute - lostMinute;
}
}
}
I saw that delay() is working correctly while moveForward() is not. To make the time notation clearer for sorting, I used String.format("%02d:%02d") to indicate the time between 00:00 and 23:59. Please note that I am not using import java.util.Calender; or 'import java.util.Date; because part of my project consists of sorting an array by just hours and then minutes. For instance, if we are trying to create the bus terminal project, we assume that the date and calendar do not matter in schedule.
public class MainTime
{
public static void main(String[] args)
{
Time t1 = new Time(23:50);
Time t2 = new Time(1:20);
Time t3 = new Time(4:50);
Time t4 = new Time(18:30);
Time t5 = new Time(14:15);
t1.delay(200);
t2.moveForward(100);
t3.delay(100);
t4.moveForward(20);
t5.moveForward(160);
System.out.println(t1.toString());
System.out.println(t2.toString());
System.out.println(t3.toString());
System.out.println(t4.toString());
System.out.println(t5.toString());
}
}
The constraints are when the change in time is greater than the minute in parameter and when the hour is going to zero. When I ran the code in NetBeans, t1 had 2:10 when I added 200 into 23:50 in delay(newMinute) method; t2 had 1:40 when I subtracted 100 from 1:20 in moveForward(lostMinute) method; t3 had 6:30 when I added 100 into 4:50 in delay(newMinute); t4 had 18:10 when I subtracted 20 from 18:30 in moveForward(lostMinute); t5 had 14:-25 when I subtracted 160 from 14:15 in moveForward(lostMinute). The variables t2 and t5 after execution should actually be 23:40 and 11:35, respectively.
Please determine which lines in public void moveForward(int lostMinute) make the improper output after subtracting the minutes from given time.
In case the minute goes to zero, 60 and modulo notation % could be useful; in case the hour goes to zero, 24 and modulo notation % could be useful. I hope for the moveForward(lostMinute) to work well in the cases when minute < 0 and when hour < 0.

java.time
LocalTime t1 = LocalTime.of(23, 50);
t1 = t1.plusMinutes(200);
System.out.println(t1.toString()); // 03:10
LocalTime t2 = LocalTime.of(1, 20);
t2 = t2.minusMinutes(100);
System.out.println(t2.toString()); // 23:40
LocalTime t3 = LocalTime.of(4, 50);
t3 = t3.plusMinutes(100);
System.out.println(t3.toString()); // 06:30
LocalTime t4 = LocalTime.of(18, 30);
t4 = t4.minusMinutes(20);
System.out.println(t4.toString()); // 18:10
LocalTime t5 = LocalTime.of(14, 15);
t5 = t5.minusMinutes(160);
System.out.println(t5.toString()); // 11:35
Output is given as comments. I think it is what you wanted. So don’t reinvent the wheel. Instead of rolling your own Time class, use LocalTime. It’s there for you to use, it has been developed and tested for you. LocalTime is a time of day in the interval from 00:00 to 23:59:59.999999999. Except that it include seconds and fraction of second it coincides with your interval. If you never set the seconds to something other than 0, they won’t be printed through the toString method. Also LocalTime implements Comparable, so sorting is straightforward.
Be aware that a LocalTime object is immutable, so instead of mutator methods it has methods that return a new LocalTime object with the new value. This is already demonstrated with plusMinutes and minusMinutes above. Also instead of myLocalTime.setHour(17); you need myLocalTime = myLocalTime.withHour(17);, etc.
What went wrong in your code?
Your moveForward method seems to be handling the hour correctly in the case where it is to be moved back to the previous hour, for example from 14:05 to 13:55 or from 14:55 to 13:05. In this case you are never subtracting lostMinutes, which I think you should somehow. When minute is 0–59, then ((60 + minute) / 60) will always be 1, so you are always subtracting exactly 1 hour, never 2 or more.
Genrally the expected ranges of the arguments to both delay and moveForward are unclear. I think they should have been documented and the arguments validated against the documented limits.
Link
Oracle tutorial: Date Time explaining how to use java.time.

Convert long to remaining time

I'm currently trying to convert a long to a remaining time. I have got a
long remaining = XXXX
The long are the milliseconds to a certain date. For example: 3,600,000 should result in int weeks = 0, days = 0, hours = 1, minutes = 0, seconds = 0
how can I convert this long so that I end up with 5 ints:
int weeks;
int days;
int hours;
int minutes;
int seconds;
Thank you in advance!
DirtyDev

First, I suggest defining the number of ms in a second, minute, hour, etc as constants
static final int SECOND = 1000; // no. of ms in a second
static final int MINUTE = SECOND * 60; // no. of ms in a minute
static final int HOUR = MINUTE * 60; // no. of ms in an hour
static final int DAY = HOUR * 24; // no. of ms in a day
static final int WEEK = DAY * 7; // no. of ms in a week
Then, you can use basic division (/) and modulus (%) operations to find what you need.
long remaining = XXXX;
int weeks = (int)( remaining / WEEK);
int days = (int)((remaining % WEEK) / DAY);
int hours = (int)((remaining % DAY) / HOUR);
int minutes = (int)((remaining % HOUR) / MINUTE);
int seconds = (int)((remaining % MINUTE) / SECOND);

Excuse me, I don’t want to criticize too much, still I gather from the other answers that it’s easy to either write code that is hard to read or code with typos that gives an incorrect result. DirtyDev, I am aware that you may not be allowed to use Duration, but for anyone else:
long remaining = 3_600_000;
Duration remainingTime = Duration.ofMillis(remaining);
long days = remainingTime.toDays();
remainingTime = remainingTime.minusDays(days);
long weeks = days / 7;
days %= 7; // or if you prefer, days = days % 7;
long hours = remainingTime.toHours();
remainingTime = remainingTime.minusHours(hours);
long minutes = remainingTime.toMinutes();
remainingTime = remainingTime.minusMinutes(minutes);
long seconds = remainingTime.getSeconds();
System.out.println("" + weeks + " weeks " + days + " days "
+ hours + " hours " + minutes + " minutes " + seconds + " seconds");
This prints:
0 weeks 0 days 1 hours 0 minutes 0 seconds
It’s not perfect, but I believe it’s both readable, correct and robust. Duration was meant for times from hours down to nanoseconds, so we still have to do the weeks “by hand”.
Happy New Year.

This should do what you want.
long inputTimeInMilliseconds = 93800000;
long milliseconds = inputTimeInMilliseconds % 1000;
long seconds = (inputTimeInMilliseconds / 1000) % 60 ;
long minutes = ((inputTimeInMilliseconds / (1000*60)) % 60);
long hours = ((inputTimeInMilliseconds / (1000*60*60)) % 24);
long days = ((inputTimeInMilliseconds / (1000*60*60*24)) % 7);
long weeks = (inputTimeInMilliseconds / (1000*60*60*24*7));
String remainingTime = "time:"+weeks+":"+days+":"+ hours+":"+minutes+":"+seconds+":"+milliseconds;
System.out.println(remainingTime);

JAVA convert minutes into default time [hh:mm:ss]

what is the easiest and fastest way to convert minutes (double) to default time hh:mm:ss
for example I used this code in python and it's working
time = timedelta(minutes=250.0)
print time
result:
4:10:00
is there a java library or a simple code can do it?

EDIT: To show the seconds as SS you can make an easy custom formatter variable to pass to the String.format() method
EDIT: Added logic to add one minute and recalculate seconds if the initial double value has the number value after the decimal separator greater than 59.
EDIT: Noticed loss of precision when doing math on the double (joy of working with doubles!) seconds, so every now and again it would not be the correct value. Changed code to properly calculate and round it. Also added logic to treat cases when minutes and hour overflow because of cascading from seconds.
Try this (no external libraries needed)
public static void main(String[] args) {
final double t = 1304.00d;
if (t > 1440.00d) //possible loss of precision again
return;
int hours = (int)t / 60;
int minutes = (int)t % 60;
BigDecimal secondsPrecision = new BigDecimal((t - Math.floor(t)) * 100).setScale(2, RoundingMode.HALF_UP);
int seconds = secondsPrecision.intValue();
boolean nextDay = false;
if (seconds > 59) {
minutes++; //increment minutes by one
seconds = seconds - 60; //recalculate seconds
}
if (minutes > 59) {
hours++;
minutes = minutes - 60;
}
//next day
if (hours > 23) {
hours = hours - 24;
nextDay = true;
}
//if seconds >=10 use the same format as before else pad one zero before the seconds
final String myFormat = seconds >= 10 ? "%d:%02d:%d" : "%d:%02d:0%d";
final String time = String.format(myFormat, hours, minutes, seconds);
System.out.print(time);
System.out.println(" " + (nextDay ? "The next day" : "Current day"));
}
Of course this can go on and on, expanding on this algorithm to generalize it. So far it will work until the next day but no further, so we could limit the initial double to that value.
if (t > 1440.00d)
return;

Using Joda you can do something like:
import org.joda.time.Period;
import org.joda.time.format.PeriodFormatter;
import org.joda.time.format.PeriodFormatterBuilder;
final Period a = Period.seconds(25635);
final PeriodFormatter hoursMinutes = new PeriodFormatterBuilder().appendHours().appendSuffix(" hour", " hours")
.appendSeparator(" and ").appendMinutes().appendSuffix(" minute", " minutes").appendSeparator(" and ")
.appendSeconds().appendSuffix(" second", " seconds").toFormatter();
System.out.println(hoursMinutes.print(a.normalizedStandard()));

//Accept minutes from user and return time in HH:MM:SS format
private String convertTime(long time)
{
String finalTime = "";
long hour = (time%(24*60)) / 60;
long minutes = (time%(24*60)) % 60;
long seconds = time / (24*3600);
finalTime = String.format("%02d:%02d:%02d",
TimeUnit.HOURS.toHours(hour) ,
TimeUnit.MINUTES.toMinutes(minutes),
TimeUnit.SECONDS.toSeconds(seconds));
return finalTime;
}

Add two String Times in java [duplicate]

This question already has answers here:
Sum two dates in Java
(9 answers)
Closed 8 years ago.
I have two String times
1:30:00
1:35:00
Is there a simple way to add these two times and get a new time which should be something
3:05:00?
I want to do this at client side , so if i can avoid any date liabraries

String time1="0:01:30";
String time2="0:01:35";
SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");
timeFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
Date date1 = timeFormat.parse(time1);
Date date2 = timeFormat.parse(time2);
long sum = date1.getTime() + date2.getTime();
String date3 = timeFormat.format(new Date(sum));
System.out.println("The sum is "+date3);
Ouput : The sum is 00:03:05

Keep in mind that you can convert int values for hours/minutes/seconds to a single int like this:
int totalSeconds = ((hours * 60) + minutes) * 60 + seconds;
And convert back:
int hours = totalSeconds / 3600; // Be sure to use integer arithmetic
int minutes = ((totalSeconds) / 60) % 60;
int seconds = totalSeconds % 60;
Or you can do arithmetic piecemeal as follows:
int totalHours = hours1 + hours2;
int totalMinutes = minutes1 + minutes2;
int totalSeconds = seconds1 + seconds2;
if (totalSeconds >= 60) {
totalMinutes ++;
totalSeconds = totalSeconds % 60;
}
if (totalMinutes >= 60) {
totalHours ++;
totalMinutes = totalMinutes % 60;
}

Use SimpleDateFormat to parse the Strings then you can add the hours minutes and seconds
something like
SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");
d1 = df.parse("1:30:00");
d2 = df.parse("1:35:00");
Long sumtime= d1.getTime()+d2.getTime();
you can see this here as well it looks like possible duplicate of #####
or if you want to use Calender API, then you can also do it using Calender API, then u can do something like
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
Calendar cTotal = Calendar.getInstance();
cTotal.add(c1.get(Calendar.YEAR), c2.get(Calendar.YEAR));
cTotal.add(c1.get(Calendar.MONTH) + 1)), c2.get(Calendar.MONTH) + 1)); // Months are zero-based!
cTotal.add(c1.get(Calendar.DATE), c2.get(Calendar.DATE));

Just sum them as you sum numbers in 1st-2nd grades, going backwards through them.
Also make sure you move over digits to higher register when needed (i.e. not
always when reaching 10 but when reaching 24 or 60 for hours/minutes).
So I suggest you code this algorithm yourself.

Clever ways to restrict integer from 100 based to 60 based for time values? (e.g.60 seconds in a minute)

I am required to store a time value in an integer in the format of HHMMSS. this time value is incrementing every second (basically a custom clock). however, since integers are naturally 10 based, I must implement a large cumbersome logic that extracts each digits and checks for 60 seconds in a minutes, 60 minutes in an hour and 24 hours a day. I wonder if there is some clever ways to do it without a massive if/else if chunk.

You can use the modulus operator to pick out each of the components of a single seconds counter:
int totalSeconds;
...
int seconds = totalSeconds % 60;
int minutes = (totalSeconds / 60) % 60;
int hours = (totalSeconds / 3600);
Then you can just increment a single seconds counter and extract each of the components.

My suggestion would be to implement a CustomClock class, which could look something like:
public class CustomClock {
private int hour;
private int minute;
private int second;
public CustomClock(int hour, int minute, int second) {
this.hour = hour;
// ...
}
public void increment() {
second = second + 1)%60;
if (second == 0) minute = (minute + 1)%60;
if (minute == 0) hour = (hour + 1)%24;
}
}
Thus taking advantage of the mod operator (%) to compute arbitrary base numbers.