Calculating a partial rent

Hi

I've just found my way here, so this is my first post :-)

Would really appreciate help with this calculation please.

A tenant’s lease started on 6th Nov 2012 with a 6 month rent free period. I now need to raise a bill to take him up to the usual quarter date (June 24th) and am unsure how many days to bill for.

Please advise if this is the correct way to calculate it:

a) From the annual rent, calculate a daily rent, by dividing by 365

b) After the rent free period, the chargeable period starts on 6th May 2013 so there are 26 days in May plus 24 days in June = 50 days to bill at daily rate.

I can imagine a different answer for every part of (b)!

Out of interest, would this be the same whether commercial or residential?

Hope someone can advise, please.

Thanks, Joy