"Sun, 18 Jan 1970 23:38:27"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
23:38:27
General datetime
1970-01-18 23:38:27Z
For Database
1970-01-18 23:38:27
For HTTP1.1
Sun, 18 Jan 1970 23:38:27 GMT