Landlord won't release keys until midday when I'm supposed to move in

My move-in date is going to be on a Sunday in a few weeks. I thought this was a little unusual, and I brought it up with the apartment manager when discussing the apartment (about a month ago). I asked her if my lease starts on this date, when is the earliest I can pick up the keys. They said it was just dependent on cleaning being completed, and that the day before Saturday would be the earliest.

I tell that would be fine. They acknowledged that move-in date was on a Sunday and said a key pickup on Saturday would be fine. Now that the lease has been signed, with the move-in date agreed upon, I'm now being told that keys will not be released until the lease begins on Sunday. And that's fine and understandable, although I am a little miffed at the change in story as I would have changed my move-in date, and would have been alright with paying for more overlap.

And here lies the main issue: their office isn't opened until 1 pm on Sunday. I'm irritated that I'm basically paying for time that I can't even enter the apartment, and they offer their opening time as "good news." As far as I see it, as soon as the clock ticks over to midnight I should have access to the apartment that I'm paying for. Of course, that's not practical, but I think anywhere in the vicinity of 8AM to 10AM is reasonable to give me the key.

And before anyone asks, no - the date of when the key can be released is not mentioned anywhere in the lease. Actually, all it mentions in regard to the key is that I'll be getting one.

I'll be calling them on Monday to discuss the issue further. And advice on what I should bring up or say? Or is this a totally normal thing?

EDIT

Well I gotta say, I am happy to have received so many responses, even if some of them were hostile. Of course some opinions I don't agree with, but the majority of the posts here brought up some good points. I will say that when writing this I was irritated, but I don't think I was being unfair to the apartment complex (though I get the feeling a couple of you were projecting from previous bad experiences, so no hard feelings). I saw that a few of you had mentioned prorated rent for the half day, but as you guys pointed out that would have been like $20, and I agree that's not worth the trouble. It's more the fact that the three of us moving in there would have all had to take off another day of work (and all the metaphorical baggage that goes with that).

If they had mentioned the afternoon key pick up date, I would have picked an earlier date. Simple as that. And to be clear, this exchange about the keys was comprised of two interactions. The first being the email asking about when I would be able to pick up the key, and the second being the phone call that took place on Monday.

Responses being complete, now for the actual update. A few of you might be upset to hear this, but the apartment complex did apologize for the miscommunication and were very helpful in arranging an earlier move in date. And would you have guessed it? The phone call didn't even take 10 minutes.

For my parting note, I must say it is extremely disconcerting to see the anti-tenant sentiment expressed by r/Landlords here. Even if it is a minority, for me it is the lasting impression of this sub. I realize that (hopefully) most users here aren't the type to spout verbal abuse at strangers, and that many who posted here didn't.

But to the posters who responded with such hostility, I have this to say - the "reason perfectly reasonable landlords get a bad reputation" is because of how you represented yourselves. To the rest of you, thank you for your feedback - it was very helpful.