"Tue, 20 Jan 1970 15:08:20"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
15:08:20
General datetime
1970-01-20 15:08:20Z
For Database
1970-01-20 15:08:20
For HTTP1.1
Tue, 20 Jan 1970 15:08:20 GMT