Custom Start Dates

So at the moment I’m paid on the last working Thursday of the month. It’s a total pain because in October (for example) there are 35 days between pay checks. The Monzo app only lets me set a recurrent date as either the x date of every month or x day recurring every 4 weeks. Neither of these are of use to me as there are some months that are effectively 5 weeks long.

Any chance we could get a set the last working x of the month? Or does anyone know of a clever workaround?