How many sunrises have you shared? Counting them exactly
“We have been together for ten years” is a sentence people say easily. “We have shared 3,652 sunrises” is the same fact, counted differently, and it tends to land with more weight. The count is not a rounding of years into days: it is the number of times the sun actually came up over the place where a couple lives.
The simple case: one sunrise a day
At most latitudes the sun rises once every day. Counting sunrises then means counting days, with one detail to get right: leap years. Ten calendar years contain either two or three 29 Februaries, so ten years is 3,652 or 3,653 days depending on where the period starts.
For central Paris, from 10 October 2016 to 10 October 2026, our calculation gives 3,652 sunrises. The span contains two leap days, in 2020 and 2024.
Where it stops being simple
North of the Arctic Circle and south of the Antarctic Circle, there are days with no sunrise at all. In winter the sun stays below the horizon (polar night); in summer it stays above it (midnight sun), and a sun that never sets never rises either.
Over the same ten years:
- Tromsø, Norway (69.6° N): 2,479 sunrises. Each year loses about seven weeks of polar night and about ten weeks of midnight sun.
- Longyearbyen, Svalbard (78.2° N): 1,254 sunrises. Here polar night runs from late October to mid-February and the midnight sun from mid-April to late August, so only about a third of the days have a sunrise.
A count that simply multiplied years by 365 would be wrong by more than a thousand in Tromsø and by more than two thousand in Longyearbyen.
Counting exactly, not approximately
To count sunrises exactly, every sunrise has to be found with the same rule used for a single sunrise: the upper edge of the sun crossing an ideal horizon with standard refraction of 0.833°. Near the edge of polar night, the sun may graze the horizon for only a few minutes, and those days count. On the first day it fails to appear, the count simply stops growing until it returns.
The starting point matters too. The count begins with the first sunrise after the moment you met, so meeting at dawn or in the afternoon can change the total by one. Local time is converted using the historical time-zone rules of the place, including any changes to daylight saving time over the years.
Milestones worth knowing
At a mid-latitude place with one sunrise a day, the counts line up with the calendar in ways that make good dates to mark:
- the 1,000th sunrise comes about two years and nine months after the first;
- the 5,000th, after roughly thirteen years and eight months;
- the 10,000th, after about twenty-seven years and four months;
- the 20,000th, a little under fifty-five years in.
A 10,000th sunrise together does not fall on a wedding anniversary or a birthday, which is precisely its appeal. It is a date nobody else will be celebrating.
When a couple has lived in more than one place
Many couples have not spent every morning in one city. A count that follows the actual places, a few years in Lisbon, then a move to Oslo, would need a record of every move. Resthe’s count uses a single place, the one you choose, and counts the sunrises there since the day you met. For most people the choice is simple: where you live now, where you met, or the place that feels like home. The number is then exact for that place, and the certificate says which place it is.
The first sunrise is the anchor
The count starts with the first sunrise after the moment you met. If you met in the evening, the first shared sunrise is the next morning. If you met before dawn, it may be the same day. When you do not know the time, choosing whether you met before or after that day’s sunrise is enough to fix the starting point.
Why polar couples have fewer, and why that is fine
A couple who met in Tromsø ten years ago have shared about 2,479 sunrises there, against 3,652 for a couple in Paris. That can look like a smaller number, but it is a more honest one. Every sunrise in the count actually happened, and every one of them is a morning the sun came back over the hills after a long night. In Longyearbyen, where the sun is absent for four months and then never sets for four more, each of the 1,254 sunrises in a decade belongs to the short spring or autumn seasons, when the days race to lengthen or shorten.
How the number is checked
The count for any place can be checked independently. Any astronomical library that implements the standard sunrise rule can list every sunrise at a point between two dates; counting them gives the same total, give or take one at the very start or end if the meeting time is uncertain. That is the point of using a published rule: the number on the certificate is a fact, not an estimate.
What the number is for
A sunrise count turns an anniversary into something you can say out loud and picture: the first sunrise after you met, and every one since, at the place you chose. It also puts the next sunrise in context. If your 3,652nd sunrise together is coming up, it is a specific morning with a specific time.
The Nth Sunrise counts the sunrises at your place from the day you met and dedicates the next one, numbered, with a premium certificate to print and frame.