Why do you want to say them? What meaning are you trying to convey?

Hiya! Just to add to Ryder's answer above, in my opinion 'Now is the morning' and 'Today is the weekend' sound unnatural to me. Some more natural options would be: It's currently morning. / It's morning at the moment. / It's morning where I am. It's the weekend. / It's the weekend today. / It's currently the weekend. Also, it would be strange to say any of these sentences to someone near you because if they are near you then they will already know this information. When do you want to use this language? I guess it is for talking to people in other countries and timezones, is that right? Hope that helps :)

1. It's morning now. That should be sufficient for a person to understand that it's not evening. 2. It's now night-time. This already explains that it is not day. We don't use repetition in English. 3. It's the weekend. Same as above. 4. It's the end of the week today!

"It's the morning now, not the evening." is pretty good Or you could just say "it's morning, not evening" Really would depend on the context of the conversation. And that goes for all your other sentences which are all fine. Which one I would choose to use as a native speaker would then depend on the context. Eg if someone wanted to try and arrange a sales meeting for Friday afternoon, I would probably say something like. " Today is the end of the week, not the beginning of the week, best to call them on Monday"

answer below, sorry >.<