android - why is current time less than a back date time in Calendar

Question

Date time set in calendar is '2016-6-18 13:54:00 ' and current date time is '2016-6-18 14:45:00' i.e. 2016-6-18 2:45 PM. In the calendar I set the MONTH value to be 5 as month is zero-based there. This is in android :

        Calendar calendar = Calendar.getInstance();

        calendar.set(Calendar.YEAR, 2016);
        calendar.set(Calendar.MONTH, 5);
        calendar.set(Calendar.DATE, 18);
        calendar.set(Calendar.HOUR_OF_DAY,13);
        calendar.set(Calendar.MINUTE,54);
        calendar.set(Calendar.SECOND,0);

        long alarmTime =calendar.getTimeInMillis();
        alarmTime = TimeUnit.MILLISECONDS.toSeconds(alarmTime);        

        long timeMillis = System.currentTimeMillis();
        long currentTimeSeconds =TimeUnit.MILLISECONDS.toSeconds(timeMillis);

        if (alarmTime > currentTimeSeconds) {

           Toast.makeText(context, "Alarm is set", Toast.LENGTH_SHORT).show();

        }else{

          Toast.makeText(context, "Alarm is not set",  Toast.LENGTH_SHORT).show();
             }

But the result shows the toast "Alarm is set" whereas I expected the otherwise i.e. "Alarm is not set".

What is going on here ?

EDIT: To my surprise, the Genymotion emulator shows 'Alarm is set' while the real device shows 'Alarm is not set'. Why is this difference ?

Code is perfect, and it is working in my local environment perfectly. Kindly recompile and run again. — Clement Amarnath, Jun 18 '16 at 09:21
Please Can you post allarmTime value and currentTimeSeconds value just before "if" instr in both emulator and real device? — christian mini, Jun 18 '16 at 12:29

score 0 · Answer 1 · edited May 23 '17 at 10:33

0

Use Calendar.getIstance().getTimeInMillis()

to compare with the first time Calendar time. Look at this answer: https://stackoverflow.com/a/16516978

in general is a good practice compare data or date generated by the same class.

edited May 23 '17 at 10:33

Community

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1

answered Jun 18 '16 at 09:34

christian mini

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didn't I do that ? – Istiaque Ahmed Jun 18 '16 at 09:38
No you did not. You are using System.currentTimeMillis() instead of calendar.getIstance().getTimeInMillisec() – christian mini Jun 18 '16 at 09:48
Where is `getTimeInMillisec` documented in developer.android.com? – Istiaque Ahmed Jun 18 '16 at 10:01
I mean getTimeInMillis() – christian mini Jun 18 '16 at 10:13
Changet System.currentTimeMillis() to Calendar.getIstance().getTimeInMillis() – christian mini Jun 18 '16 at 10:24
Why should that make any difference ? – Istiaque Ahmed Jun 18 '16 at 10:30

score 0 · Answer 2 · answered Jun 19 '16 at 22:24

Sounds like a time zone issue.

Note that Calendar.getInstance() creates a Calendar object using the default timezone (i.e. the time zone that's configured in the device settings).

So if your Genymotion emulator is set to UTC the created Calendar object represents 2016-06-18 13:54:00 UTC which is 2016-06-18 14:54:00 GMT+1

If your device is in GTM+1, the created Calendar object represents 2016-06-18 13:54:00 GMT+1.

To fix this make sure you call Calendar.getInstance(ZimeTone) passing the correct time zone that's associated with your alarm.

android - why is current time less than a back date time in Calendar

2 Answers2