You typically parse a timestamp like "1999-03-29 20:02:04 CEST" and return a number of seconds since a given point in time (e.g. UNIX epoch if it must be).
There's your conversion. I'm not saying it's not easy, I'm saying you're just pulling you out of a hole that your tools were configured to dig.
There's your conversion. I'm not saying it's not easy, I'm saying you're just pulling you out of a hole that your tools were configured to dig.