昼間は誰も家にいないって英語でなんて言うの？

Any of the above phrases will make it clear that there is nobody in the house during the daytime on working days. If someone is asking you to look after their pet, but you are not able to because no-one is at home during the day, you could add more information in order to be more polite in your refusal. For example: 'I would love to help you if I could, but there is no-one at home during the daytime, as everyone is at work. So we couldn't let the animal(s) out, feed them or walk them.'

In the day, nobody's in' ... so perhaps you should come by after 6pm.

When would you use this, perhaps to explain to someone how your family unit works or perhaps if you have to explain to someone delivering something that no-one is going to be there in the day to receive delivery. It depends whether you are talking to a friend or to a supplier. To a supplier/service person I would use no. 1 or 2, to a friend I would use no. 3 in conversation.

You can say the house is "left empty" during the day. You can also refer to the members of your family as "the household" (a family unit). For the time of the day when the house is empty, we could say "during the day" or "daytime hours."

House is empty is a very common phrase used in America and the West when describing a house that isn't full of people. Empty would refer to the lack of individuals in the house. It doesn't literally mean your house is empty of furniture and other things! Only means that there aren't people. Of course, that phrase is also used to literally mean an empty house ie: when you're moving to a new one. A: "Hey can I come by tomorrow at 1 pm?" B: "The house is empty tomorrow during the day. Everyone's at work." Good luck!

Using time expressions like: "While" or "during" can tell you that several things are happening at the same time.