If you’re comfortable with this schedule then go for it. If you think after completing physics within 1 month , you can complete bio and Chem in the rest months and at the same time , remember whatever you’ve studied in physics 1 month back – then go for it.
Else, I would suggest you .. don’t do it in that way because when you are practicing physics for 1 month – a time will come when you’ll feel boring after solving physics for so many days. During that boring time, you won’t feel like doing physics and at the same time, since in your “schedule” you haven’t kept Chem and bio – so you won’t study those subjects for mood change. Ultimately , you’ll be the one losing time both for physics and for Chemistry biology. You might think “why will such a thing happen? I won’t get bored solving physics all day long “ – but dear, I’ve been through it . Maybe you won’t feel the same but there are chances that you might feel what I’m saying.! So , it’s better if you study all the 3 subjects together . Start with physics., after sometime when you’ll feel ‘ahh.. my mind isn’t working anymore’ – sit with biology. Read biology. After that when you’ll feel ‘Ohh I’m so done with biology..getting bored’ – switch to Chemistry. What I’m saying is learn to switch subjects alternatively and study. In that way you won’t feel bored of studying one subject all day long and at the same time, all 3 subjects would be equally finished