Three members of the Polaris Middle School girls' soccer team had the following conversation.

David: I just realized that our uniform numbers are all 2-digit primes.

Emily: And the sum of your two uniform numbers is the earliest date we've mentioned this month.

Fiona: That's funny. The sum of your two uniform numbers is the middle date we've mentioned this month.

David: And the sum of your two uniform numbers is the latest date we've mentioned this month.

What number does David wear?