Typically meetups happen on the same day of the week.

Examples are

• the first Monday
• the third Tuesday
• the Wednesteenth
• the last Thursday

Note that "Monteenth", "Tuesteenth", etc are all made up words. There was a meetup whose members realised that there are exactly 7 days that end in '-teenth'. Therefore, one is guaranteed that each day of the week (Monday, Tuesday, ...) will have exactly one date that is named with '-teenth' in every month.