Allow a setting for release dates on 'Notes'.

The ability to set an expiration date on 'notes' is great, but I also would benefit from a release date! We put out our Solo/Duet/Trio offers via Notes on each of the dancers profiles, and share it with the parents. In order to be able to release them all at the same time rather than having some dancers show up before others, it would be great to have a release date option.