Dates and Times

Leverages the Field API to add registrations to any entity. Also leverages workflows to control processing registrations, and has Commerce integration for paid registration requirements.

Provides options for adding a link to your date output. An example use would be linking to your group's meetup page to RSVP, or directing users to a registration webform. By default links will only be added to upcoming events, but this module can be configured to add its links to all events.

Proof of concept for using Smart Date with Drupal Commerce to allow registration. This module will define a product type for listing events. If only using this system for free events, you can update the form display to remove the price and potentially the sku fields, and you will likely want to implement a simplified checkout process.