title: android adding or removing hour from timestamp in database
body: <p>I want to subtract a few days from my timestamp in Android.</p>
  
  <p>I have an <a href="https://en.wikipedia.org/wiki/SQLite" rel="nofollow noreferrer">SQLite</a> database with a date field of the type long.
  When I execute a query where I say <code>date = date - (3 * 86400000)</code> I sometimes experience a one hour difference as a result when converting it to a readable date.</p>
  
  <p>But how is this possible? Has it to do with the daylight savings of one hour in my timezone?</p>
  
  <p>Because I would find it strange if that's the reason because you are doing calculations with two long values and after converting them back to datetime there shouldn't be a daylight saving issue?</p>