I've just applied to change my hours at work so I finish at 3pm every day, meaning I now work 80% of my full time hours. I was previously entitled to 25 days holiday but they're saying that will reduce to 20
(I.e. 20% less). I understand the logic, but I'm still working every day and losing a whole week's holiday is going to be pretty significant for me. The reason I'm cutting my hours is because I have no childcare outside of school! My pay is already reducing by 20% so taking a weeks leave from me on top seems unfair.
Surely, since in each day I work 20% less hours, when I am on leave I am also taking 20% less leave. So, I should still get 25 days (but am taking 20% less hours each day). I already argued this to HR but they refused, and sent me a policy which very clearly states the calculation and says if you're part time on e.g. 80% hours, you get 80% leave even if you work 5 days a week. This seems wrong to me but they refuse to give in.
Has anyone else been in a similar situation and managed to argue successfully? Am I being unreasonable to expect a bit more from a company who claims to support women who need flexible working arrangements?