Help hiding a button based on a datetime field

I’ve been looking for a calendar plugin which can restrict when people can click a “book now” button. The events have a finite period beforehand when bookings are allowed, from the first Sunday in the month, for two weeks.
I’ve found Modern Events Calendar which looks good and allows me to have a link to a Gravity Form on the booking/more info button, but now what I need to do is disable the button if booking is not available. Currently I’m doing this using Elementor Visibility plugin which allows me to hide a button if booking is not yet open, or the window has passed, and then show “booking not yet open” or “bookings have closed” in the same way.
Now I guess I need to create a hook or some code to disable the booking button if the current date is not within 3 weeks of the event.
Can anyone provide any pointers please? Thank you