New sellers answer support at midnight because every message feels urgent. It is a habit that ends in burnout and, oddly, in worse reviews.
Expectations are set by your fastest reply
Answer three messages within ten minutes and the fourth buyer, waiting four hours, feels ignored. You have not slowed down, you have simply stopped being extraordinary, and the contrast is what they notice.
State the hours, then meet them
"Support answered within one working day, Monday to Friday" is easy to keep and impossible to be disappointed by. A buyer who gets a reply in three hours against that promise is delighted rather than merely satisfied.
Put it where it will be read
Your store bio, your documentation, and the item page. Not only in a reply once somebody is already waiting.
Batch the work
Twice a day beats continuously. Support answered in a block is answered better, because you are in that frame of mind rather than being interrupted mid-feature.
Going away
Say so in advance, in your bio and in your item descriptions, with the date you return. A buyer who knew before purchasing waits patiently. One who discovers it after paying does not, and that is the difference between a shrug and a one-star review.