Quick hack to display certain number of multiple datefields?

Hiya - I notice that if I add a select list style datefield to a content type and check 'unlimited' under multiple values, it gives me the ability to enter four dates, not 'unlimited.' What I'd really love is if I could tell it to let me enter three dates - I'm working on a site where a user can enter up to three performance dates for a play, and they aren't allowed to have more than three. i don't want to make a separate datefield for each performance. Any ideas? I looked at the module code trying to see where the number of fields is printed but I couldn't figure it out.