title: Timestamp used in Google Timezone API
body: <p>I want to add my flight event to outlook using ICal.cs.</p>
  
  <p>For example, I have a flight on July 10, 7:30am from Toronto, YYZ airport.</p>
  
  <p>I want to use Google Timezone API to return the raw offset and DST offset to me, so I can calculate the local flight time in UTC format and used in my ICal file.</p>
  
  <p>The Google API below requires to pass the timestamp. I wonder they requires a timestamp of UTC time or not?</p>
  
  <p>This is their description of this value:</p>
  
  <p><strong>timestamp</strong> specifies the desired time as seconds since midnight, January 1, 1970 UTC. The Time Zone API uses the timestamp to determine whether or not Daylight Savings should be applied. Times before 1970 can be expressed as negative values.</p>
  
  <p>I can get latitude and longitude for YYZ airport, but how do I calculate this timestamp for my flight time if I don't know the time offsets in advance?</p>
  
  <p><a href="https://maps.googleapis.com/maps/api/timezone/json?location=43.700113788,-79.416304194&amp;timestamp=1419283200&amp;sensor=false" rel="noreferrer">https://maps.googleapis.com/maps/api/timezone/json?location=43.700113788,-79.416304194&amp;timestamp=1419283200&amp;sensor=false</a></p>
  
  <p>This is what it returns:</p>
  
  <p>{
     "dstOffset" : 0.0,
     "rawOffset" : -18000.0,
     "status" : "OK",
     "timeZoneId" : "America/Toronto",
     "timeZoneName" : "Eastern Standard Time"
  }</p>