After adding the custom code below to your site, you can update the Date Format for your forms in your Global Settings.

This example assumes you have two forms set up: one for the event and one for reservations. The event form will include a field for the number of available openings. The reservation form will include a Dynamic field to list all the events. This function will drop the number of available openings for an event when it is selected.

Use this code to limit the maximum number of characters accepted in a field.