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javatimetimestamplong-integermilliseconds

Java: Convert long time of day to timestamp

I have a long value that represents the time of day in milliseconds since midnight that day. i.e. 00:00:01 would be 1000.

I want to convert this to a long timestamp since the epoch - using the current System's day, month, year. What's the best way to do this?

Solution 
  •     final Calendar instance = Calendar.getInstance();
    instance.set(Calendar.HOUR, 0);
    instance.set(Calendar.MINUTE, 0);
    instance.set(Calendar.SECOND, 0);
    instance.set(Calendar.MILLISECOND, 0);
    long result = instance.getTimeInMillis() + yourTime;

    Also note that Calendar#getInstance does the following:

    Calendar cal = createCalendar(TimeZone.getDefaultRef(), Locale.getDefault());

    The resulting time will change according to the default set TimeZone (and yes it can change !). See this post: java Timezone setDefault effects