"Tue, 13 Jan 1970 20:42:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700113
Only TIME
20:42:21
General datetime
1970-01-13 20:42:21Z
For Database
1970-01-13 20:42:21
For HTTP1.1
Tue, 13 Jan 1970 20:42:21 GMT