"Tue, 20 Jan 1970 20:38:04"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700120
Only TIME
20:38:04
General datetime
1970-01-20 20:38:04Z
For Database
1970-01-20 20:38:04
For HTTP1.1
Tue, 20 Jan 1970 20:38:04 GMT