mysql php postgresql sqlite timezone

how do you deal with timezone issues?

For a scheduling system, what’s the best way to save the timezone of client/event in a central server database coming from multiple sources mobile,web,client app.

  • How do you store the dates? Alarms, reminders etc…
  • How do you handle the DST setting?
  • How do you handle the events if client has traveled to a different location?

I need the solution to work with all databases in tags.