"Wed, 21 Jan 1970 20:42:33"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700121
Only TIME
20:42:33
General datetime
1970-01-21 20:42:33Z
For Database
1970-01-21 20:42:33
For HTTP1.1
Wed, 21 Jan 1970 20:42:33 GMT