heretofore vs til now

heretofore and til now both are adverbs.

Word	Noun	Adjective	Verb	Adverb
heretofore	No	No	No	Yes
til now	No	No	No	Yes

As adverbs, heretofore and til now are synonyms defined as:

heretofore and til now: used in negative statement to describe a situation that has existed up to this point or up to the present time

Other synonyms of heretofore include as yet, hitherto, so far, thus far, until now, up to now, yet.

heretofore (adverb)	til now (adverb)
used in negative statement to describe a situation that has existed up to this point or up to the present time	used in negative statement to describe a situation that has existed up to this point or up to the present time