title: Google spreadsheet - how to determine timezone using function
body: <p>How to use a formula to determine the current timezone?
  The formula I use gives an unexpected result.</p>
  
  <p>My spreadsheet settings (File > Spreadsheet settings...):
  Time zone: <strong>(GMT+01:00) Amsterdam</strong></p>
  
  <p>The formula I used:
  <strong>=TEXT(NOW(),"HH:mm z")</strong></p>
  
  <p>This gives:
  <strong>12:47 GMT</strong></p>
  
  <p>Local clock time is 12:47, I would expect the formula to show: "<strong>12:47 GMT+1</strong>".
  I also tried Z instead of z, which gives "12:47 +0000", I would expect +1.</p>
  
  <p>Any suggestions?</p>
  
  <p>I need this so I can determine UTC time and convert to Epoch time ("UTC time" - DATE(1970,1,1)*24*60*60)</p>