"Sun, 18 Jan 1970 12:31:47"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
19700118
Only TIME
12:31:47
General datetime
1970-01-18 12:31:47Z
For Database
1970-01-18 12:31:47
For HTTP1.1
Sun, 18 Jan 1970 12:31:47 GMT