Derwentmailman

My state pension will start next year in early April 2024 (i.e within the 23/24 tax year) when I reach SPA, but I won't receive any payments on it until the next tax year (i.e. post April 6th 2024) and could be nearly 5 weeks into the new tax year but less if I elect weekly payments (but still after April 6th into the 24/25 tax year). I currently receive 3 occupational pension and already pay a small amount of income tax. At what point should HMRC be informed about my state pension commencement? Or will this be done automatically after I have indicated that there is no deferment? Will I need to work out the number of days pension I get in this current tax year even though I won't be in receipt of an state pension payments until the following 24/25 tax year?