"Sat, 03 Jan 1970 20:42:37"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700103
Only TIME
20:42:37
General datetime
1970-01-03 20:42:37Z
For Database
1970-01-03 20:42:37
For HTTP1.1
Sat, 03 Jan 1970 20:42:37 GMT