I do like knowing when sunset is though. A second or two won't matter, but after some decades all the formulas for calculating sunset time will be wrong.
Note that moving 30 km (or 20 miles) east or west also changes the sunset by one minute.
Depending on how close to the poles / equator you are, and probably also time of the year.
Of course a photographer would start well before sunset and continue well after, but if you want to program a machine to photograph su sets you will end up having to use techniques other than checking the time.