How many letters does the top answer for “wrote night and day” have?

The most common answer is porter (6 letters).

Crossword clue: wrote night and day

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

porter 6 letters wd-fact-v3

someone who guards an entrance

wrote night 67% similar → wiesel

author of night and day 50% similar → porter

composer of night and day 50% similar → porter

wrote boogie nights 50% similar → reynolds

wrote burmese days 50% similar → orwell

wrote night flight 50% similar → saintexupery

wrote night watch 50% similar → lukyanenko

wrote tender is the night 50% similar → fitzgerald