How to set Calendar according to Timezone

Question

I want to make a Calendar according to Timezone. I tried to resolve the issue by surfing different queries but i can't. Now it pick mobile default time. If anyone have idea please help me. Timezone should be UK time.

I tried:

{
    Calendar c1;
    c1 = Calendar.getInstance(TimeZone.getTimeZone("UTC"), Locale.UK);
    int hour = c1.get(Calendar.HOUR);
    int minutes = c1.get(Calendar.MINUTE);
    int seconds = c1.get(Calendar.SECOND);
    int day = c1.get(Calendar.DAY_OF_MONTH);
    int month = c1.get(Calendar.MONTH);
    int year = c1.get(Calendar.YEAR);
} 

But it also returns System date.

Answer 1

java.time

    ZonedDateTime nowInUk = ZonedDateTime.now(ZoneId.of("Europe/London"));
    int hour = nowInUk.getHour();
    int minutes = nowInUk.getMinute();
    int seconds = nowInUk.getSecond();
    int day = nowInUk.getDayOfMonth();
    Month month = nowInUk.getMonth();
    int year = nowInUk.getYear();

    System.out.println("hour = " + hour + ", minutes = " + minutes + ", seconds = " + seconds 
            + ", day = " + day + ", month = " + month + ", year = " + year);

When I ran this snippet just now, it printed:

hour = 3, minutes = 41, seconds = 15, day = 5, month = OCTOBER, year = 2018

ZonedDateTime largely replaces the outdated Calendar class.

What went wrong in your code?

Time zone ID for UK time is Europe/London. In your code you used UTC, which is something else and wll give you a different result, at least sometimes. UK time coincides with UTC some of the year in some years, but not at this time of year this year. So you got a time that was one hour earlier than UK time.

Also c1.get(Calendar.HOUR) gives you the hour within AM or PM from 1 through 12, which I don’t think was what you intended.

Question: Can I use java.time on Android?

Yes, java.time works nicely on Android devices. It just requires at least Java 6.

• In Java 8 and later and on new Android devices (from API level 26, I’m told) the new API comes built-in.
• In Java 6 and 7 get the ThreeTen Backport, the backport of the new classes (ThreeTen for JSR 310, where the modern API was first described).
• On (older) Android, use the Android edition of ThreeTen Backport. It’s called ThreeTenABP. Make sure you import the date and time classes from package org.threeten.bp and subpackages.

Links

• Oracle tutorial: Date Time, explaining how to use java.time.
• ThreeTen Backport project
• ThreeTenABP, Android edition of ThreeTen Backport
• Question: How to use ThreeTenABP in Android Project, with a very thorough explanation.
• Java Specification Request (JSR) 310.

Answer 2

Use this method for get time from timezone but here is one condition must need to checked auto time in setting's otherwise move to setting's page.

 private void setDateTime() {
//        Settings.Global.putInt(getContentResolver(), Settings.Global.AUTO_TIME, 1);
        try {
            int value = Settings.Global.getInt(getContentResolver(), Settings.Global.AUTO_TIME);
            if (value == 1) {
                Log.i("value", String.valueOf(value));
                {
                    TimeZone.setDefault(TimeZone.getTimeZone("Europe/London"));
                    String pattern = "yyyy-MM-dd HH:mm:ss";
                    SimpleDateFormat simpleDateFormat = new SimpleDateFormat(pattern, new Locale("en", "in"));
                    String date = simpleDateFormat.format(new Date());
                    Log.i("get C_d_t", date);
                    txt_time.setText(date);
                }
            } else {
                //move to settings
                Toast.makeText(getBaseContext(), "Must need to checked automatic date & time", Toast.LENGTH_SHORT).show();
                startActivityForResult(new Intent(android.provider.Settings.ACTION_DATE_SETTINGS), 0);


            }
        } catch (Settings.SettingNotFoundException e) {
            e.printStackTrace();
        }


    }