Can I restrict the frequency with which user can submit a form?

Form block - conditional visibility

And yes, an Airtable formula can set a field value to 1 or 0 if a form has been submitted or not in the same calendar month.

Formula could be:

One possible formula to enter a field value of 1 if a user has submitted a form in the same calendar month is:

IF ( DATETIME_FORMAT ( {Submission Date}, ‘YYYY-MM’ ) = DATETIME_FORMAT ( TODAY (), ‘YYYY-MM’ ), 1, 0 )