If one day of your week runs to a different time from the others, callers could be told the wrong one. Asked what time you close, your receptionist was reading your opening hours as a block and could quote the time most of your days end at rather than the time that particular day ends at. On a business open late one evening a week, that is the evening customers were told you were already shut.
The hours for the day being asked about are now worked out before your receptionist answers, so it quotes that day's line and no other — whether the caller asks about today or names a day. Tested against a business open later on Thursdays than the rest of the week, it now gets it right every time.
Where a caller is asking about an appointment rather than the door being open, your bookable timetable still governs, and your receptionist says so instead of promising a slot.