"Sun, 15 Feb 1970 19:40:42"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700215
Only TIME
19:40:42
General datetime
1970-02-15 19:40:42Z
For Database
1970-02-15 19:40:42
For HTTP1.1
Sun, 15 Feb 1970 19:40:42 GMT