APEX

Dear community,

first of all, I am using Apex 3.1 on Oracle 10g, if this is necessary to know (yes I know, an old version, but given by the company I'm working for). After I've developed a few applications in Apex, thank to the forum and all the answers inside, I came to a problem that I could not solve:

I want to have a normal text field, where the user can enter a duration of an event (e.g. "3:45" or "2:30"). That duration will allways be in the format "MM:SS". No hours, no milliseconds... But how can I save the given values in the database, so in which format? A varchar would be a possibility, but I want to build a report later on, where there is a sum of the times. And how to get a sum of varchar?! But how to make it clear to Apex and Oracle DB that the users gives in a time and not a varchar? The only thing oracle offers is a date field, but I want to save a time and not a date!

Does anybody has a clue for me, cause it seems to me, that possibly I just don't know what I'm searching for, cause people must have had this problem before!?

THanks for your help!

Regards
hoge