IANAL. Also IDKWYL (I don’t know wher you live), but in the sane Western world (the EU), there’s no need for a notice in your case - usually it’s a good idea to check with the landlords/tenants wether they plan on renewing the lease or not so you both know where the other side is standing.

And, of course, since the contract is time-bound, the assumption is that both possibilities (renewal and no renewal) are on the table, and neither require any side to go out of their way to announce their intent on what happens after the contract expires.

The ‘default’ option is no renewal - otherwise there is no meaning in making it time-bound and burdening the parties with the need to re-establish a new agreement each contract term. So the need to give a notice of “I plan to do xy after the contract” makes no sense, let alone it carrying contractual punishments.

You weren’t required to give a notice. Even if the contract stated so, that clause would most likely get nullified (again, in most of Europe).

Again, IANAL. You should get one.

But, were I your lawyer (which I most definitely am not), I would scold you for writing the notice since it puts you in a submissive position (your landlord can now claim that by giving notice you “showed” that you “think” you “owe” the landlord notice, ergo you owe them money for the 2 days in May (assuming a 30-day notice), which they conveniently round up to an entire month.

Of course, this makes no sense. The contract meets its natural end by the date given and that’s it. No notices, no payments, no apartment rented out.