Can I add two extra fields for inputting time and date delivery wanted?

Hope someone can help -
I am building a system for a food take away store and need to have a pop up time and date box or two extra time/datefields so the user can state the time and date that they require delivery.
Preferably done so that I can only make certain times/dates available for delivery.
Using Zen cart version 1.3.8a.
Many thanks.

There are two 'delivery date' mods in the Free Software Add Ons, but neither tracks time, so you have some coding ahead of you, using one or both of them for ideas.

Many thanks you for your quick reply. In the absence of a module that allows time to be stated it does indeed look like a lot of trial and error ahead, hopefully someone will beat me to it and make their solution public.
I can't believe that nobody has come across this lack of time/date support for required deliveries before.
But overall, Zen cart seems to be an excellent system and congratulations to all those involved.