Form Scheduler add-on for Google Forms can limit the number of responses and schedule to open or close the form based on the google calendar events. Trial limitations: - Accept during calendar events feature will cease functioning after 7 days Free features: - Stop after Maximum responses - Stop at specific date Features: - Schedule to collect form responses based on google calendar entries - Ability to schedule variable or fixed number of responses for every event occurances with overall maximum limit - Allow or stop accepting responses for recurrence events - Allow or stop accepting maximum responses for each recurrence events E.g. A lawyer or doctor can create appointment bookings by creating an accepting response event in the calendar and setting the daily limit to 20 or variable number of clients. - Stop reponses when maximum number of responses are reached - Stop responses after a specific date and time - Create schedules as once, hourly (90 minutes apart), daily, weekly, monthly, yearly with calendar recurrence - Custom closed message specification - Auto email creator after specified responses are collected - Error reporting - The number of emails to be sent/day, trigger(s), it's run time etc. are restrained by your Quotas for Google Services. For details visit: https://developers.google.com/apps-script/guides/services/quotas IMPORTANT: - Works best in Google Chrome - Sometimes (rare circumstances) the scheduled calendar events may be activated with a lead/lag of +-60 minutes. Hence, this is not recommended for minute precision, complex workflows.