"Sat, 03 Jan 1970 00:40:15"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
00:40:15
General datetime
1970-01-03 00:40:15Z
For Database
1970-01-03 00:40:15
For HTTP1.1
Sat, 03 Jan 1970 00:40:15 GMT