Early Decision on Rolling Basis?

bruhhhhhh

Apologies if the question is too broad -- I'm wondering if anyone knows whether early decisions are always on a "round" basis (as in timing of submission has zero impact on admission decisions, as long as submitted by the deadline), or whether there are instances in which they operate on a rolling admissions basis. I can't seem to find any information that disproves or confirms either option on law schools' websites (e.g. Northwestern).
Thank you!