Compute the unix timestamp for the previous midnight

Question

How can you, in Java, compute the unix timestamp truncated to midnight?

PHP examples show making strings and then parsing them back. There has to be a cleaner way to do it in Java than that, surely?

Answer 1

Unix timestamp starts from midnight UTC so we can do the following

Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
long unixTimeStamp = c.getTimeInMillis() / 1000;

Answer 2

Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
c.set(Calendar.HOUR,0);
c.set(Calendar.MINUTE,0);
c.set(Calendar.SECOND,0);
c.set(Calendar.MILLISECOND,0);

long midnightUnixTimestamp = c.getTime().getTime()/1000;