title: Querying for a date constraint
body: <p>I've done research on this question and thought I found the answer which makes sense but it's not working so i'm not sure if I'm making a silly mistake.  I want to query for data that is created in the past week, month, year,..etc.  I looked at my data already uploaded to parse and to test it out, I wanted to query for the data from the past 5 days.  For some reason, it finds 0 objects when there should be five objects created after August 8th.  When I switched to lessThanOrEqualTo it found all 9 objects even though there's 4 objects created before August 8th.  Any clarity on this. Thanks</p>
  
  <pre><code>NSDate *then=[NSDate dateWithTimeIntervalSinceNow:-7200];
  PFQuery *query=[PFQuery queryWithClassName:@"urinationAmount"];
  [query whereKey:@"user" equalTo:[PFUser currentUser]];
  [query whereKey:@"createdAt" greaterThanOrEqualTo:then];
  urinationDataArray=[query findObjects];
  NSLog(@"Objects in Array:%i",urinationDataArray.count);
  </code></pre>