Boss is telling us not to clock in on tomorrow’s holiday to avoid paying us double time – is that legal?

I work at a small art gallery and our boss is telling us that we're supposed to work tomorrow but not to clock in because he'll have to pay us double time. Instead, he wants us not to clock in and he'll pay us our normal hours, and then give us holiday pay for a weekend or something. Is that okay? I am torn. Does it even out? I am in the USA.