As explained by "flyingron," the law is no more than $150 or 5% of your monthly rent (whichever is more. $60 is 5% of $1,200, so $60 per month is within the legal limit.
I'll bet your landlord thinks it isn't fair that you didn't pay your rent on time. In any event, it appears the relevant statute of limitations is three years, so the landlord may only be able to deduct for the past three years. How much in total is at issue?

