The reason I use time and date is that those sunrise/set times are not theory , they are direct observation , or reality .
I thought I'd have one last go at persuading you, so here goes.
How are time and date's sunrise/set times direct observations? In other words how is it possible for me to look up a direct observation for a sunrise time on 23rd Sept 2019 when it hasn't happened yet?
The reality is that they use an agreed technical definition of sunrise/set -
when the centre of the sun is 50 arcminutes below the horizon - to make mathematical predictions. This figure is derived from the 16 arcminute angular radius of the sun plus 34 arcminutes - an accepted average figure to account for refraction. If atmospheric conditions differ at your location on the day or you are not at sea level, sunrise/set will differ by a small amount.
On an equinox day, wherever you are, if you time from when the centre of the sun hits the horizon on the rise to the same point when it sets, you will get close to 12h. Sunrise to sunset will take a longer time however because the sun must travel the extra 50 arcminutes (twice).
Go on over to your favourite site
https://www.timeanddate.com/calendar/autumnal-equinox.html and look up the autumnal equinox for Longyearbyen, Svalbard, Norway (way, way north) and it'll tell you it's on 23rd Sept 2019. Now check sunrise and sunset times for that date and you'll find they're 12:30 apart. The extra 30 minutes is the time it takes for the sun to travel those extra 100 arcminutes.