Yes this is a correct sentence.
The teacher announce that tomorrow is a holiday.
Yes, "tomorrow" can be considered a subject in a sentence. It refers to the day after the current one and can act as the main focus of a statement or question. For example, in the sentence "Tomorrow is a holiday," "tomorrow" serves as the subject.
is it holiday tomorrow
yes tomorrow will be the postal holiday
is tomorrow is holiday for idukki
No
no
No, tomorrow is a holiday, except in Austria.
Yes. Tomorrow is chhat Parva
In the sentence "tomorrow is a mystery," 'tomorrow' is a noun functioning as the subject of the sentence.
yes