You can say either one, but I'd probably use the first sentence rather than the second.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
In the States, you will almost never hear anyone say "It's Sunday today." They would probably just say "It's Sunday."
You would hear "Today is Sunday," but I'd think you'd hear it more as a prelude to a longer conversation than as a singular statement. For example, one might say, "Today is Sunday, and the package will arrive in 14 business days, so that means it will pro