I don't mean like to the minute or anything, even "morning, early afternoon" etc would do! DH's family come to stay with us a few times a year, they live 200 miles away so it's not like we're down the road and they stay two nights each time. They will tell us a day they're coming (not ask when is good for us, but tell us(!)) and then don't bother to say when they're coming at all during the day. The few times they have been pinned to a time they've then consistently arrived hours later and not communicated that they're running late.
Current example is that SiL and her friend who we've never met are coming to stay at ours as they're going to an event tomorrow evening in the city we live in (I don't mind them staying to save on a hotel fee, I'm not a complete arsehole). However we've heard nothing about when she's planning to get here. DH is at work all day so it's me and two young DC + the dog at home. I said to DH this evening I think it's inconsiderate to not even say at all when she's planning to get here as it means I don't know whether I can go out tomorrow or when to walk the dog, whether they'll be joining us for any meals etc. DH won't contact her to ask and says his family just work differently to mine (I was brought up to always give people some indication when hosting of when you intend to arrive, I still do it with my parents now as an adult). I've said I think it's rude as it implies that my time is less valuable than hers so I can jusy fit around her plans as she decides them. I leaning towards just going out during the day and if they happen to get here and I'm not there to let them in then that's her fault for not communicating at all. (In the past she's literally called to say "surprise, I'm on the motorway heading to see you" so I don't respond well to visitors when I'm not expecting them!) 🤦🏻♀️
AIBU to think it's just being considerate / polite in these situations to let someone know in advance roughly when you plan to leave/ arrive?