Integration of customer accepting estimate booking time

I would like there to be a feature when someone fills out the booking form with there requested day when I confirm a date to send to them I think it would be a great idea for them to have a confirm or deny button before the appointment goes onto the google calendar. Things happen fast in life and there day could not be available anymore, as-well as I have a team of door knockers I don’t speak to the clients myself. When i send the quote on site estimate the email could get lost if they have a messy inbox or whatever reason it is I would really not like to show up at someones door that doesn’t know or didn’t notice the booking time. So i think that adding accept or deny feature would be a great help for myself or anyone else experiencing the same thing.