"Wed, 21 Jan 1970 04:35:36"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
04:35:36
General datetime
1970-01-21 04:35:36Z
For Database
1970-01-21 04:35:36
For HTTP1.1
Wed, 21 Jan 1970 04:35:36 GMT