Time zones in database

Hello everyone,

just a quick explanation of my situation. I have car rental webapp, the customers will be able to book their cars even when they are outside the country, which means their “current user” time zone is used in the process, but the time they are booking in reality in my time zone, so when the booking is saved to the data base is saved as in their own time zone, and I see it converted to my own.

As an admin I should be able to view, edit and delete the booking. I use the AirDate/TimePicker which allows to select specific timezone but when the user navigates in the website I send the selected dates in the url or store it to their “user” thing and the two ways when I display it on the date picker again it adds the offset in timezone by itself, am I getting this wrong, or the whole “Timezone” thing in the the date picker should stay to default?