"Thu, 01 Jan 1970 20:37:21"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700101
Only TIME
20:37:21
General datetime
1970-01-01 20:37:21Z
For Database
1970-01-01 20:37:21
For HTTP1.1
Thu, 01 Jan 1970 20:37:21 GMT