Quote Originally Posted by John_Douglas View Post
ru.wikipedia.org/wiki/Сутка
LOL! Well, native speakers can correct me if I'm wrong, but I suppose that in theory, it would be possible to construct a sentence like:

Перевозить посылку за границу вообще стоит меньше, чем за Сутку.
Meaning, "Transporting a package across the border generally costs less than (transporting it) across the Sutka river."

So, the combination of words меньше чем за Сутку is not totally impossible, but it's rather unusual, and means "less than (going) beyond the Sutka (river)."

But as already had been said, if you mean "in less than 24 hours", it would be меньше чем за сутки, using the accusative plural, because сутки ("a timespan of 24 hours") is a word like ножницы ("scissors") that is never used in a singular form.