ILR application submission date

Hi!

My current visa (Refugee) is valid until 22 September 2025. I was checking on gov.uk to know when I should apply for ILR. The website states: "You should apply during the last month of your current permission to be in the UK."
So is that a calendar month (as in I can only apply in September) or 30 days count?
I used the mobile app to verify my id, do I need to book and submit biometrics as well?

Any help and/or advice will be greatly appreciated.

many thanks

The rules do not care about when you apply for the ILR application. The general advice is to apply before visa expiry and when you are eligible, which is 28 day before reaching your 5 years. For your biometrics, you will be given the options after application submission