Help! “My Wife is Asking We Draw a Timetable For Sex”

Is it okay for a married couple to draw up a timetable for having sex?

My wife is complaining that I disturb her every day and that she can no longer cope. She has insisted that we come up with a timetable of two days in every week and stick to it. This means she is ready to give me sex only twice a week.

Also, how many times per week is ideal for a couple to have sex?