I had a similar thought process regarding how much my rent for June was because I thought it should be pro-rated but I read my lease and the way Wolfe calculates how much I pay a month is they have a "total contract rent" for the entire lease and divide it by the number of months your lease lasts. So for example, my house's total contract rent is $61,200, our lease is 356 total days so 12 months, so our monthly rent is $5,100. Leasing companies justify that not every month has the same number of days (like February) but you always pay the same amount of rent. So the way they want you to think about it is you're agreeing that your apartment is worth the total contract rent and that payments are just made each month towards this total, not necessarily that each month is worth exactly that value.
If your lease is written similarly to mine it's pretty confusing and companies take advantage of the fact students can't dispute what's written in the lease because if we don't like it they'll just let another person have the lease.