Symptom: While being in the PST/PDT time zone, if you use 10:00 PM in the "Starting at Approximately" field you will not see games before 10:00 PM. If you enter 9:00PM you do see games up to three hours earlier and later. I'm assuming in your code it has something to do with the Date/Time comparison and the date rollover of server time.
Screenshot of 10:00 PM search:
Screenshots of games you see when entering 9:00 PM:
Screenshot of 10:00 PM search:
Screenshots of games you see when entering 9:00 PM: