Allow date to be cleared in triggers and automations

Original thread:
https://support.zendesk.com/hc/en-us/community/posts/204253097-Reminder-system-unable-to-clear-date-field-once-the-reminder-has-been-sent

With the date field, it is only possible to set an action to:

• Set to a specific date
• Set to a number of days from now

It isn't possible to clear the field. See here:

The use case for this feature:

• Will allow the "Remind me!" to work without excluding tickets from a report
• Allow us greater flexibility when working with date fields

If you have any other use cases, comment so I can update the post.