WHQ doesn't care when you meet, as long as it's at least 12 times a year -and they don't enforce that

.
Last time I researched it, there were about 100 clubs that have two different meeting days/times.
Here's an example:
1st Sunday / 3rd Tuesday, 9.30 am / 7:00 pm
I think the reason there are so few clubs is that most people prefer regular schedules.
However, there's no reason for your club not to try it.
George