明日 and 翌日: tomorrow and the following day
Compare an expression anchored to the speaking day with one anchored to an event.
The day after speaking
明日 (あした) normally means the day after the speaking day. 「明日、出発します」 says the speaker will leave tomorrow.
「明日までに送ります」 sets a deadline of tomorrow for sending it. It does not restrict sending to tomorrow alone.
The day after a reference event
翌日 (よくじつ) means the day after a previously identified day. 「注文した翌日に届きました」 says it arrived the day after ordering.
In 「月曜日に着いて、翌日に帰りました」, 翌日 is Tuesday. It is anchored to that Monday, regardless of when the story is told.
Preserving the date relationship
「旅行の翌日は家で休みます」 says the speaker will rest at home the day after the trip. Whether that is tomorrow depends on the trip's date.
Automatically translating 翌日 in a past story as tomorrow changes the timeline. First identify the day serving as its reference point.
In a story about arriving last Monday, which day does 翌日 identify?
Show the answer and why
The Tuesday after that Monday, not the day after the current speaking day.