How many letters does the top answer for “from this time forth; from now on” have?

The most common answer is henceforth (10 letters).

Crossword clue: from this time forth; from now on

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

henceforth 10 letters wn-def

from this time forth; from now on

henceforward 12 letters wn-def

from this time forth; from now on

at this time or period; now 50% similar → currently