Calculating overall tax bill given new property income split during financial year

Hello. On 12th March 2024 I submitted to HMRC a Form 17 declaring a change in the beneficial interests in income between my partner and myself arising from a rental property (changing from the previous default 50/50 split). Given that the 23/24 tax year runs from 6 April 2023 to 5 April 2024, I would like to know how I account for the following in my 23/24 self assessment tax return: - From 5 April 2023 to 11th March 2024: 50% of income. -From 12th March 2035 to 5th April 2024: New split of income. Do I need to calculate this manually and provide some sort of explanation in the any other information section of the self assessment tax return? Thanks.

Hi,
Yes, you would need to calculate this manually and you could show your calculation in the additional information box of your tax return. 
Thank you.