It would be really helpful to just be able to set our own custom appointment recurrence intervals, i.e. add a "Custom" option to the "Recurring" dropdown menu and have 2 fields that we can complete, one for time interval (days, weeks, months) and one for the number of that iterval. i.e.
"Repeat every {number} {interval}"
and/or
"Repeat every {interval} on {day(s) of week}"