"Sun, 18 Jan 1970 14:44:35"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
14:44:35
General datetime
1970-01-18 14:44:35Z
For Database
1970-01-18 14:44:35
For HTTP1.1
Sun, 18 Jan 1970 14:44:35 GMT