Anniversary Years: How to Count Years Together and Milestone Names

Learning how to calculate anniversary years is the simplest way to answer a question every couple asks sooner or later: how many years have we actually been together? Whether you are planning a celebration, ordering a gift, or just settling a friendly debate, the count matters, because a 10th anniversary and a 10th year together are not always the same thing. The method is straightforward once you know which date counts as the starting point and how completed years differ from the year you are currently in.

This guide walks through the counting method step by step, explains the traditional milestone names, and finishes with a worked example you can check against the Anniversary Calculator.

The Method / Formula

An anniversary count has three parts: the starting date, the as-on date, and the number of full years between them. The starting date is the wedding date, or the joining date for a work anniversary. The as-on date is the date you are counting to, usually today. The result is the number of anniversaries already completed, which is the same as the number of full years that have passed since the starting date.

To work it out, subtract the starting year from the as-on year. Then check whether this year’s anniversary has happened yet: if the as-on month and day fall before the starting month and day, subtract one, because that year’s anniversary has not arrived. The figure left is the number of anniversaries completed. Days together is a separate count: the plain calendar difference between the two dates, which is zero on the starting day itself and grows by one each day after it. The next anniversary is simply the starting month and day in the next year that has not yet passed.

Two points of wording are worth pinning down. First, the number of anniversaries completed is not the same as the year you are in: on your 10th anniversary you have completed 10 years and are starting your 11th year together. Second, days together counts real calendar days, so leap days are included automatically; that is why 10 years together comes to 3,653 days rather than 3,650.

How to Count Your Anniversary Years Step by Step

1. Write down the starting date: the wedding date, or the joining date for a work anniversary.
2. Write down the as-on date, usually today, or the date you want to count to.
3. Subtract the starting year from the as-on year to get a first figure.
4. Check this year’s anniversary date: if the as-on date falls before it, subtract one from your figure.
5. The result is the number of anniversaries completed; match it to the milestone list for the traditional name.
6. For days together, count the plain calendar difference between the two dates, and take the next anniversary as the starting month and day in the following year.

Worked Example

Take the example shown on the tool page: a wedding on 10 June 2015, counted as of 10 June 2025. Subtracting the years gives 2025 minus 2015, which is 10, and because the as-on date falls exactly on the anniversary date, no adjustment is needed. The couple have completed 10 anniversaries, which makes it their Tin anniversary, and the next anniversary falls on 10 June 2026.

Days together is the calendar difference between the two dates. Ten ordinary years would be 3,650 days, but the span includes three leap days, 29 February 2016, 2020 and 2024, giving 3,653 days together.

The traditional milestone names are: 1 Paper, 2 Cotton, 3 Leather, 4 Fruit & Flowers, 5 Wood, 6 Iron, 7 Copper, 8 Bronze, 9 Pottery, 10 Tin, 15 Crystal, 20 China, 25 Silver, 30 Pearl, 40 Ruby, 50 Gold.

Common Mistakes / Good to Know

• Counting the wedding year as year one. The wedding day itself is day zero: you complete your first year on your first anniversary, not on the wedding day.
• Calling the current year the completed count. If you married in 2015 and today is in 2025 before 10 June, you have completed 9 anniversaries and are in your 10th year together.
• Multiplying years by 365 for days together. Leap days add up: 10 years together is 3,653 days, not 3,650, because 2016, 2020 and 2024 were leap years.
• Treating milestone names as fixed everywhere. Lists vary a little: the 10th gift is tin, or aluminium in some lists, and the 60th is diamond in most lists. The same counting works for work anniversaries too; simply ignore the gift names.

Frequently Asked Questions

Once you can count years together this way, try the Duration Calculator for gaps measured in days, hours and minutes, and read our guide How to Calculate Time Duration Between Two Dates next for the same date-difference idea applied to times.