Whats the sweet mileage spot?

i’ve been following the general rule that anything over 800 miles should be a two day transit but what I’m finding is when I try to book these loads carriers seem to want to do them next day even up to 900 or 950 miles. what are your thoughts? When does next day transit turn into two day transit keep in mind almost all my facilities load and unload 7 to 3 and no weekends.