UK LoCo fixed pattern 50% part time i.e. 4 on/4 off/5 on/15 off. So, 9 days work in every 28. 14 days annual Leave which I usually use as single days of Leave to reduce the 5 day block to 4. Preference bidding in advance for 2 sector late duties normally successfull, if not I can normally get what I want using the Open Flights system (uncrewed duties).