"Sat, 14 Feb 1970 14:45:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700214
Only TIME
14:45:21
General datetime
1970-02-14 14:45:21Z
For Database
1970-02-14 14:45:21
For HTTP1.1
Sat, 14 Feb 1970 14:45:21 GMT