Night light, sunset and sunrise times in Gnome

[Anil Felipe Duggirala]

hello,
I am running Gnome in Debian Buster, which comes with the Night Light
feature. I have set up night light in the Sunset/Sunrise setting. I
have also correcly set my timezone (location?). My issue is, sunset is
coming and Night Light is gettin activated way after this time. I would
like to ask how I can know where the program is getting my location's
sunset time from?  Is there a way for me to check this? 
thank you,