I like to equate the eight solar festivals to a day. That puts the winter solstice at midnight, Imbolc in the wee hours of the morning, Samhain sometime between sunset and midnight, and so on. The summer solstice is equivalent to high noon. The time of the actual solstice varies from year to year, and can be at night which just does not work for me metaphorically. So I prefer to celebrate it at noon on whatever day it falls.
Years ago, it occurred to me that noon isn’t 12:00 PM in summer because of Daylight Saving Time. “Noon” in the sense of the time that the Sun is at its high point, is actually 1:00 PM (“spring ahead”). Well, that’s an easy enough change if I remember it, which I don’t always, because “noon” and “12:00 PM” are synonymous in my mind.
But you can get even geekier about this if you want to. Up until the nineteenth century, each community kept “local time.” But with the development of railways, people could travel so quickly that they had to change their watches in town after town as they moved east or west, and it made scheduling difficult. Out of this came time zones and the adoption of a generic time that’s the same for all communities within a zone. This makes life easier in many ways, but I wanted to know when local noon would have been for where I live. Living in an apartment, setting up a sundial wasn’t all that practical. Luckily, you can figure this out if you know where you are, where your time zone is based, and how long it takes the Sun to move a certain distance. So, to give you something without much use except for the occasional ritual or meditation, I present a method of finding your local noon.
(No, your ancestors didn’t do this. They didn’t have to—local time was normal for them.)
Just to make it clear, this will not tell you the exact moment of the summer solstice. You can skip all this math and look the time and date up when you need to.
- It’s summer: remember to start your calculations at 1:00 PM instead of noon. You could stop at this point and be pretty accurate.
- Find the longitude of your location. You could Google it (“Boston, MA longitude”), or heck, there are apps that will tell you where you are. You want the number with the W (west), not the N (north).
- Boston, MA: 71.0589º W
- St. Paul, MN: 93.0936º W
- Longitude is often shown in degrees and minutes, but in looking up the longitude for my city, I realized that it’s also shown as degrees and a decimal, like I listed above. To convert that decimal to minutes, multiply the decimal by 60.
- Boston, MA: 0.0589 x 60 = 3.534′ which rounds up to 4′. Boston’s longitude is 71º 04′ W.
- St. Paul, MN: 0.0936 x 60 = 5.616′ which rounds up to 6′. St. Paul’s longitude is 93º 06′ W.
- Look up the meridian of your time zone:
- Chances are, there’s a difference of at least a few degrees between your location and your time zone’s meridian. The time it takes the Sun to travel between the two is the difference between the generic noon for your time zone and your local noon. So now, calculate the difference between the two, subtracting the smaller number from the larger.
- Boston, MA: 75º – 71º 04′ = 3º 56′.
- St. Paul, MN: 93º 06′ – 90º = 3º 06′.
- Now you convert units of longitude into units of time (ooh, aah!). At the rate the Earth rotates, the Sun moves 15º of longitude in an hour. But you probably aren’t that far away from your time zone’s meridian, so we need smaller units.
|Longitude Units||Time Units|
- Boston, MA: 3º x 4 minutes = 12 minutes. 56′ is three chunks of 15′ (that is, 45′) which are another 3 minutes of time, plus the leftover 11′ which adds 44 seconds of time. 12 minutes + 3 minutes + 44 seconds = 15 minutes, 44 seconds, or 16 minutes of time for people without a stopwatch.
- St. Paul, MN: 3º x 4 minutes = 12 minutes. 6′ x 4 seconds = 24 seconds. 12 minutes + 24 seconds = 12 minutes, 24 seconds, which is just 12 minutes of time, practically speaking.
- And now to find the time of your local noon! Add or subtract that time you just came up with to 1:00 pm (remember Daylight Saving Time). If you’re east of your time zone’s meridian, subtract your time difference. If you’re west of your time zone’s meridian, add your time difference.
- Boston, MA: Boston is east of the Eastern Time Zone meridian, so high noon will come just a bit before 1:00 PM. 1:00 – 16 minutes = 12:44 PM EDT.
- St. Paul, MN: St. Paul is west of the Central Time Zone meridian, so high noon will come just a bit after 1:00 PM. 1:00 + 12 minutes = 1:12 PM CDT.
Joyous Solstice to you!