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?
I think it's the point when the centre of the Suns disk crosses the horizon.
From the same web site.
I may be wrong but my understanding is it is the time that the leading edge raises above the horizon for sunrise and when the trailing edge dips below the horizon for sunset. Dont forget that sunrise/set times will differ for different parts of the country. The further west you are the later the times will be.