My extreme apologies if this is the wrong forum. (I considered Weather or Physics, but I didn't think they were appropriate)
This site here lists the sunset/sunrise times for Dublin for each day
For example, today, the sunset time is listed as 21:07 and the sunrise time is listed as 05:37.
My question is: what actually happens at this time? What does this exact time mean? Surely you can't narrow a sunset down to one minute - isn't it not a gradual event.
Can anyone shed some light on this?