Date of the UK part of year begins

Hi HMRC Admin, I have arrived the UK on Sept 16, 2022 and have rented a house which the effective date of the tenant agreement started on Aug 1, 2022 and have lasted for a year. Please advise when is the date from which the UK part of the year begins ? This piece of information is needed to submit SA109, where Box 6 is asking the date of the UK part of the year begins. Thank you,

Hi,

You can see guidance here:

RDRM12150 - Residence: The SRT: Split year treatment: Case 4: Starting to have a home in the UK only

Thank you.