Depends on how long it took before symptoms appeared or you tested positive.
10 full days of isolation ending on (but including) the 24th would mean 1st day of isolation on the 15th, which means getting a positive test result on the 14th.
You don't have to wait for symptoms. You could have a test on the 14th just in case if you think there is a chance you are positive and are otherwise going to be a hermit until Christmas.
Depends on how long it took before symptoms appeared or you tested positive.
10 full days of isolation ending on (but including) the 24th would mean 1st day of isolation on the 15th, which means getting a positive test result on the 14th.