Calculate the date of meetups.
Typically meetups happen on the same day of the week.
Examples are
- the first Monday
- the third Tuesday
- the Wednesteenth
- the last Thursday
There are exactly 7 days that end in '-teenth', therefore one is guaranteed that each day of the week will have a '-teenth' in every month.
Jeremy Hinegardner mentioned a Boulder meetup that happens on the Wednesteenth of every month view source