Just wondering if someone can check my maths!! Have name changed in case my boss works out it’s me 
So our holiday year this year runs 1 May 2021 - 30 April 2022. I am returning from maternity on 2 August, when I’ll be going down to a 4 day week, with Mondays as my non working day. I’ve been on statutory maternity throughout (no enhancement, if relevant). Standard allocation for full timers is 25 days plus BHs. My understanding is that my allocation is calculated as follows:
STEP 1 - during maternity. 3 months of usual allocation (so 25% of 25 = 6 days) plus all the bank holidays in that time (2 days) so total 8 days for this part.
STEP 2 - on return from maternity, 80% of full time. 19 days remain in this section of the year, and 6 bank holidays in this time = 25 days. 80% of 25 is 20 days. Because I’m not working Mondays I then subtract all the non-Monday bank holidays during that time, of which there are 2. So total for Step 2 is 18.
To get my total allocation until 30 April 2022 I then add those figures together so 8 + 18 = 26 days.
Is that right? I think it is but it seems weird that I’ve got more A/L days than I would get as a full timer despite spending a quarter of the year on maternity and going down to 4 days!!
Thank you in advance 