use google calendar appointment slots: NAF: "I hope there's always a slot in the calendar year for an ... . Customize your appointment availability - Google Calendar .... Appointment Booking Calendar – Plugin WordPress.
In this blog post, we will go deeper on how to create
appointment slots in Google Calendar, so you can make sure you're always on top of your schedule.
Google Calendar just added bookable appointment scheduling, and it's pretty sweet. ... Even if you assign a block of bookable appointments to a non-default calendar, it will still show up in your default calendar as well.
When Google Calendar syncs with SSA to check for conflicts, your personal Google Calendar Events can block off your Booking Calendar
time slots.