"Sat, 21 Jun 2025 14:45:15"
Convert date and time to unixtime.
Another datetime format string at UTC
YYYYMMDD
20250621
Only TIME
14:45:15
General datetime
2025-06-21 14:45:15Z
For Database
2025-06-21 14:45:15
For HTTP1.1
Sat, 21 Jun 2025 14:45:15 GMT