yes
No, it is more correct to say, "What day is it today?"
Yes, by the end of today is correct. It's not a complete sentence, though.
Wednesday morning, it is correct to say I have not seen him for one day. Wednesday afternoon, or by working day end, it is correct to say I have not seen him for two days
Yes, you can say that; we've got today to get this job done.
The correct phrase is "today's meeting." Using the possessive form "today's" indicates that the meeting is happening on the specific day that is being referred to.
No, it is more correct to say, "What day is it today?"
It is grammatically correct to say , "I am in school today." This is because you are in the building, not at the building.
Yes.
Yes, that sentence is grammatically correct.
It is correct, but it would be nicer to use the baby's name, as in "How is Johnny today?"
"We were informed it will be corrected today" is a correct sentence. However, it might sound a little better to say "We were informed that it will be corrected today."
Yes, by the end of today is correct. It's not a complete sentence, though.
Wednesday morning, it is correct to say I have not seen him for one day. Wednesday afternoon, or by working day end, it is correct to say I have not seen him for two days
Yes, you can say that; we've got today to get this job done.
no you would say we or you me and him!1
Neither, apparently, see related links.
No. For example, it is perfectly correct to say, "It was very hot today."