"Wed, 21 Jan 1970 01:01:38"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
01:01:38
General datetime
1970-01-21 01:01:38Z
For Database
1970-01-21 01:01:38
For HTTP1.1
Wed, 21 Jan 1970 01:01:38 GMT