How hard is it to know exactly to the second when the sunrise occurs? You would think one click on the internet would do it but a few things make it slightly harder. The calculation has to know exactly where you are on earth. It also needs to know your elevation and the elevation of the horizon. All three are pretty easy here on Cape Ann. You don’t have to be within the foot, just a decent guess.

So if I am standing about 30 feet above the water and the sunrise is on the water, boom, 2/3rds done. Then you go to Sunrise Tools at this website and do some clicking. You can have a free account so once you have your favorite locations saved it’s easy.

Today, the sunrise was at 7:10:55 AM and tomorrow it will be 22 seconds later at 07:11:17 AM. Most internet calculators will round that off so that both happen at 7:11 AM. But if you want to see the green flash in the morning you need precision to the second.

That way I could figure out that my phone died precisely eleven seconds before sunrise.