Can I I say "today is holiday " the days I dont need to go to work And am off?

A holiday (in America) is specifically government-recognized days of celebration or remembrance. For example, Christmas is a holiday. Sunday and Saturday are the weekend, not a holiday. "Today is my day off" or "I have today off" would be how to convey it. If it is a day you usually don't have off work, you would say "I'm on vacation" or "I'm taking a vacation" in the US. Alternately, "I'm taking a personal day" (which can mean time off for personal well-being or mental health) or "I'm taking a day off" (taking indicates it's not normally a day off for you).

You could also say, “Today’s my day off/one of my days off,” or, “I’m off today/I have today off/I’m not working today.” Edit: This is for the U.S. (and changed some words).

In addition to what others gave said I've heard "I'm taking today as holiday" used in the UK. This would apply if you were using your paid leave for a day off work.

No. To begin with, grammatically it must be: "Today is **a** holiday." In the U.S. "Today is a holiday" would mean it is a day like Christmas or Easter. To communicate your intended meaning, you would say: "Today is a day off." In the UK *holiday* (as in "I'm on holiday") means time off from work, such as for a vacation. I'm not sure if in the UK "Today is a holiday" can be applied to a single day off or not, but certainly not to a regular day off or to a schedule that happens to give some days off and some not (such as working shifts at a restaurant).

"Today is a holiday" in British/Canadian/Australian English if it is an actual holiday (such as Christmas) or if you are using your vacation leave ("I'm going on a holiday") Not if it's a weekend. In the US, a holiday is only used for actual holidays (such as Christmas).

Not in American English

Australia: You would need to say “today is **a** holiday” and that would only apply to days which are public holidays, eg. New Year’s Day. Otherwise, if you have taken time off, you can say “I’m **on** holidays.” If it’s just one day you’re not at work, “I’m off today.”

All the above..plus you could just say "I'm not working today" or "I'm taking" or "I'm having" a day off.

It depends on the context, but “today is holiday” sounds strange. If it’s a regular day off e.g you’re just not scheduled to be in that day, you’d say “today is my day off” or “today is one of my days off” If you’re off work because of a national celebration for example Christmas or any other bank holiday, then you could say “today is a holiday”. If you’ve booked time off work at a random point in the year, I would usually say “I’m on annual leave.” You could also say “I’m on holiday”, but that could imply you’re on a trip if the person doesn’t know that you aren’t. I don’t usually use “holiday” unless it’s referring to an actual trip I’m taking or if it’s a national holiday.

USA Today is a holiday.