Develop Reference

Difference between two Times in Minutes are coming as negative

I have a method which takes two String parameters. the two strings are Time values in 24 hour format. The Times are picked using a TimePicker from UI.
The goal of the method is to get the duration between the StartTime and EndTime in Minutes.
public static String getTimeDuration(String StartTime24, String EndTime24)
{
String duration = "";
try
{
SimpleDateFormat parseFormat = new SimpleDateFormat("HH:mm");
Date startTime = parseFormat.parse(StartTime24);
Date endTime = parseFormat.parse(EndTime24);
long mills = endTime.getTime() - startTime.getTime();
long minutes = mills/(1000 * 60);
duration = "(" + minutes + " Minutes)";
}
catch(ParseException ex)
{
// exception handling here
}
return duration;
}
The method works fine if both the times are within a Single Date. For example:
StartTime = 22:15
EndTime = 23:51
Output = (96 Minutes)
But my problem is, the method returns negative if the end time is after 12'o clock at night. For example,
StartTime = 23:51
EndTime = 0:55
Output = (-1376 Minutes)
What I want: (64 Minutes)
How can get the duration correct ?

As there is no date used, you have to check first if your endTime is less than your startTime. If yes, then your endTime is on the next day and you have to add 1 day/86 400 000 milliseconds. Then you will have your desired result.
Just add this condition:
if(endTime.getTime() < startTime.getTime()){
long mills = ((endTime.getTime() + 86400000) - startTime.getTime()); 1 day = 86 400 000 mill
}
Hope this helps

You're only parsing the minutes and hours. There's no day on there. So that puts both times on the same day (the first day of the epoch, Jan 1 1970 to be exact). So the answer is correct. If you want it to treat the end time as the next day if its earlier than the start time, then add 1 day to the result (1440 minutes) if the result is less than 0.

Change DateFormat depending on Days passsed

Essentially what I have is a string which contains a files Last Modified Date. To get this I'm using:
Date lastModDate = new Date(file.lastModified());
SimpleDateFormat formatter = new SimpleDateFormat("K:mm a");
String formattedDateString = formatter.format(lastModDate);
The end result is somewhat like 6:12 AM. What I want to do is each time a certain period of time is passed, the dateformat must change. E.g.
After 1 Day has gone by, Last Modified Date = ("Format1");
After a Week has gone by, Last Modified Date = ("Format2");
After 2 Weeks have gone by, Last Modified Date = ("Format3");
Does it make sense? If so is someone please be able to show me how it's done. A good example is the native Messaging App. When a message is created, It will show it's Time then after some days gone by the format changes to the Date it was created then the month etc...
I'm trying to do exactly that.

Calculate the difference in time between the last modified date and now:
long duration = lastModDate.getTimeInMillis() - current.getTimeInMillis();
long sec = TimeUnit.MILLISECONDS.toSeconds(duration);
boolean inFuture = sec > 0;
// Use positive value
if(!inFuture)
sec = -sec;
long minutes = sec / 60 % 60;
long hours = sec / 3600 % 24;
long days = sec / 86400;
if(days > 1 && days < 7)
// Use format 1
else if(days >= 7 && days < 14)
// Use format 2
else
// Use format 3

How to compare two timestamps in android?

I want to compare two timestamps and if the difference of that is (-+5minuts) then I want to display alert dialog.
i.e. If currently in our watch 4PM the second time is 4.05PM or 3.55PM then alert will display else not.
Can anyone suggest me the way how can I get the solution of this.??
I found after search the function of getting timeStamp and how to compare two timestamps but for this type of condition is there any method or function?
Thanks.
My code is:-
date= new Date();
currentTime = date.getTime();
if(currentTime !=0 && previousTime !=0){
String result = (String) DateUtils.getRelativeTimeSpanString(currentTime, previousTime, 0);
}
And I am storeing current time in to previous time lilke tis way :-
if(currentTime != previousTime){
previousTime = currentTime;
}

There's two approaches you could take, depending on whether you just want to measure time elapsed, or want to set future times to compare to.
The first is similar to Sourabh Saldi's answer, record the result from
long prevEventTime = System.currentTimeMillis();
then compare it with System.currentTimeMillis() until the difference is more than 300000
As you have mentioned, your timestamp from the server is in milliseconds since January the 1st, 1970. This means it is directly comparable to System.currentTimeMillis(). As such, use:
long serverTimeStamp=//whatever your server timestamp is, however you are getting it.
//You may have to use Long.parseLong(serverTimestampString) to convert it from a string
//3000(millliseconds in a second)*60(seconds in a minute)*5(number of minutes)=300000
if (Math.abs(serverTimeStamp-System.currentTimeMillis())>300000){
//server timestamp is within 5 minutes of current system time
} else {
//server is not within 5 minutes of current system time
}
The other method looks closer to what you're already doing - using the Date class to store the current and compared time. To use these, you'll want to be using the GregorianCalendar class to handle them. Calling
calendar=new GregorianCalendar();
will create a new calendar, and automatically set it's date to the current system time. You can also use all the functions supplied in the GregorianCalendar class to roll the time forward or backward using something of the form
calendar.add(GregorianCalendar.MINUTE, 5);
or set it to a Date object's time with
calendar.setTime(date);
In your case, depending on how much flexibility you want both the GregorianCalendar class and the Date class have after() methods, so you probably want something like the following:
Create somewhere:
Date currentDate=newDate();
Then set your alarm point:
calendar=new GregorianCalendar(); //this initialises to the current system time
calendar.setTimeInMillis(<server timestamp>); //change to whatever the long timestamp value from your server is
calendar.add(GregorianCalendar.MINUTE, 5); //set a time 5 minutes after the timestamp
Date beforeThisDate = calendar.getTime();
calendar.add(GregorianCalendar.MINUTE, -10); //set a time 5 minutes before the timestamp
Date afterThisDate = calendar.getTime();
Then check if the current time is past the set alarm point with
currentDate.setTime(System.currentTimeMillis());
if ((currentDate.before(beforeThisDate))&&(currentDate.after(afterThisDate))){
//do stuff, current time is within the two dates (5 mins either side of the server timestamp)
} else {
//current time is not within the two dates
}
This approach can seem a bit more long winded, but you'll find it is very robust and flexible, and can easily be extended to set alarm points far in the future, or use the GregorianCalendar methods to easily set dates hours, days or weeks into the future.

How about just:
private static final long FIVE_MINUTES = 1000 * 60 * 5; //5 minutes in milliseconds
long currentTime = new Date().getTime();
long previousTime = mPreviousTime;
long differ = (currentTime - previousTime);
if (differ < FIVE_MINUTES && differ > -FIVE_MINUTES ){
// under +/-5 minutes, do the work
}else{
// over 5 minutes
}

long etime = 0;
final long time1 = uptimeMillis();
/* do something */
final long time2 = uptimeMillis();
if (time2 < time1) {
etime = Long.MAX_VALUE - time1 + time2;
} else {
etime = time2 - time1;
}
then check this etime and do as required!!1

Use this following method to change your dates in epoch format
public Long getChnagedDate(Activity act,String date) throws ParseException
{
long epoch = new java.text.SimpleDateFormat ("MM/dd/yyyy HH:mm:ss aa").parse(date).getTime();
return epoch/1000;
}
and after check the difference in http://www.epochconverter.com.
Hope it helps you.

Joda time will help you with this task.
import org.joda.time.Interval;
http://joda-time.sourceforge.net/

Is there an existing algorithm for comparing dates/longs to Minutes?

I want to compare a "now" long/date value minus a "last notification time" long/data value to an integer value representing an interval of minutes before a new notification is made.
I know I cannot simply do this:
bool bItIsTime = (iMinutesBetweenNotifications < (lLastNotificationTime - lRightNow));
...but what is the way to do it. If the value of "now" is 42.2468, would 41.2468 be yesterday at this time? IOW, does 1.00 == 1 day? (in which case 0.1 == 144 minutes, 0.01 == 14.4 minutes, etc.)?

If you are extracting the long value of the last notification time from a Date or Calendar object, the value is usually the number of milliseconds since January 1, 1970 GMT. This is also the same units that you get from System.currentTimeMillis(). You can do your test like this:
long now = System.currentTimeMillis();
bool bItIsTime = iMinutesBetweenNotifications * 60000 // convert to milliseconds
> now - lLastNotificationTime;
if (bItIsTime) {
issueNotification();
lLastNotificationTime = now;
}

Chronometer set wrong long value

Set manually long value to chronometer.my long value is correct but when I set this to chronometer.setBase()it display specially character instead of correct time.
// hourInt = 4
// minInt = 34
// secInt = 40
Calendar cal1 = Calendar.getInstance();
cal1.set(Calendar.HOUR, hourInt);
cal1.set(Calendar.MINUTE, minInt);
cal1.set(Calendar.SECOND, secInt);
long codeBase = cal1.getTime().getTime();
System.out.println("Code Base..."+codeBase);
chronometer.setBase(codeBase);
chronometer.start();
it display special chraracter like 00:0) and 00:0* and all special character.
how to set custom long value.

I was struggling with this myself until I managed to figure it out through trial and error.
Chronometer.setBase() wants millis based on the elapsed real time. This means that epoch milliseconds don't work. In order to be able to use epoch milliseconds, you have to call Chronometer.setBase() like this:
chronometer.setBase(SystemClock.elapsedRealtime() -
System.currentTimeMillis() + codeBase);
The math effectively converts the epoch milliseconds to elapsed real time milliseconds.