Indeed, you are welcome!
No worries; the (60 days leave + 20 days PTDY + 10 days post clearance equals) NLT 90 calendar days for military disability transition is the maximum date that a military service member must be retired/separated from military service.
That said, please coordinate with your military pay office (MPO) and RSO/transition office for the optimum date which meets your specific personal requirements. It seems that you already have 60 days of leave so just determine the approximate number of days for post clearance activities (i.e., five days); therefore, you would request a total of 65 days for military disability separation with severance pay.
Moreover, if post clearance activities can be completed within one day, then you could request 61 days for military disability separation with severance pay; your overall actions shall dictate the total amount of time needed to complete all requirements with MPO and RSO/transition office.
Thus, I quite often comment that "possessing well-informed knowledge is truly a powerful equalizer."
Best Wishes!