2 things, where are you located and are you talking reserve or reg force?
cause courses start in different times, and in different locations.
For reserve BMQs starting now they usually run every other weekend. till may Sometimes however, due to schedualing some courses run 2 weekends in a row or maybe every weekend straight for 10 weeks
For reg bmqs, im not sure of the starting date but they will run for 13 weeks consecutive.