Is it possible to make a custom post's title take the value of a custom field?

Here's what I'm trying to accomplish: I'm creating a custom post type that is a "daily pollen count" (for an allergist client). The posts won't need titles; I would like to somehow force the title to take the value of a date-picker custom field (for example: "May 1, 2013"). That way the person publishing the day's pollen count won't need to manually type "May 1, 2013" in the title field.

I tried disabling the title field in the custom post type configuration within CustomPress, but the post takes the title "Auto Draft" automatically when I publish it (which shows up as the post's title - which I can easily hide by modifying the php template) but it ALSO shows up as the post's slug, which is a problem.

Any ideas?

Thanks in advance!