SA 109 Box 10 days enquiry

Dear Sir, I came to UK on 18 Aug 2022 and started my only home in UK. I will apply for split year treatment. For the box 10 of SA109 form, I am confusing what total number of days should be filled in. Is it (a) the total number of days in UK before I came to UK or (b) total number days in UK after I came to UK? May I ask which number of days applies, (a) or (b)? Best regards, 

Name removed admin .

Hi

Only fill in box 10 if you put ‘X’ in any of boxes 1, 2 or 3.
Put the total number of days during the 2022 to 2023 tax year when you were in the UK at midnight.  
Have a look at the guidance notes for box 10 at Residence, remittance basis etc notes for more details.

Thank you