That has among its meanings "lasting 24 hours" and also "a changing of day to night, back, or both". A single human is not likely to be equally active the whole

That has among its meanings "lasting 24 hours" and also "a changing of day to night, back, or both". A single human is not likely to be equally active the whole 24 hours. Although I do know of some people who basically nap around the clock and don't sleep in an extended block, they seem to be a rare exception. It seems like a decent word to stretch a little into this use of the idea that members of a species may have different familial, social, or individual circadian activity. I hesitate to do that though, because I'm unaware of it being used that way to date and it seems it could be difficult in such a context to differentiate it from established meanings of the word.