The end date of the overseas part of the tax year under split year treatment

Hi HRMC admin, I have been working for my employer in Hong Kong for about 30 years until I resigned from the employment with the last working date of my Hong Kong’s employment on 2 March 2022. I have no UK ties and was not resident in the UK in the past. On 15 June 2022, I moved to the UK using a BNO visa. I sold my only home in Hong Kong in September 2021 and then lived in a hotel in Hong Kong before moving to the UK. I arrived in the UK and stayed in hotels while I found a house to rent. Later I signed a 18 month rental contract on a house in the UK, and the rental period commenced on 30 June 2022. I was unemployed in the UK during the tax year 2022-2023, and remain in the UK since 15 June 2022. I will apply for Case 4 split year treatment for the tax year 2022-2023 since I have other income such as overseas bank interest. Grateful if you would let me know the end date of the overseas part of the tax year. Should the end date be 30 June 2022 or 15 June 2022 or other date? I do not meet the criteria for other Cases split years. Thank you. Regards, 

Name removed admin .

Hi S Chung,
The overseas end date will be the midnight before the day in which you arrived in the UK.
Midnight is used as a fixed point.
Your first day in the UK is the first midnight that you were in the UK.
Split year treatment should be declared on the tax return supplementqary page SA109.
Residence, remittance basis etc (Self Assessment SA109)
Please have a look at:
RDRM10610 - Residence: General Information: Counting days
Thank you.