How do you calculate years, months, and days?

We use direct calendar arithmetic. First, full elapsed calendar years are determined from your start date. Then, remaining whole calendar months are counted. Finally, the remaining calendar days between the last month anchor and the calculation date are totaled.

When is a 6-month or half anniversary?

A 6-month anniversary falls exactly six calendar months after your start date (for example, January 15 to July 15). If the start date is on the 31st and the 6-month mark falls in a month with fewer days, the date automatically adjusts to the last day of that month.

How does the calculator handle February 29 (Leap Day) anniversaries?

In leap years, the anniversary falls on February 29. In common non-leap years (which have only 28 days in February), our tool deterministically marks the calendar anniversary on February 28, with a clear note that some couples also choose to celebrate on March 1.

What are day milestones like 100 days or 1,000 days?

Day milestones celebrate round numbers of total days together. Popular relationship milestones include 100 days, 500 days, 1,000 days, and 10,000 days. Our calculator lists these dates chronologically.

Can I use this for work service or memorial dates?

Yes. Simply enter the start date of employment, founding date of a project, or memorial date. The optional occasion selector adjusts the summary phrasing accordingly.

Anniversary Calculator

Find out how long it has been since your wedding, first date, employment start, or any milestone date. View total calendar days, when your next anniversary arrives, and upcoming milestones with zero fuss.

How Anniversary Calculations Work

Unlike simplistic tools that approximate months as 30.44 days or divide years by 365, our anniversary calculator uses true Gregorian calendar arithmetic. It steps forward using completed calendar months and exact calendar days, matching how people naturally count anniversaries.

Calendar Month & Year Arithmetic

Counts completed calendar years first, followed by whole calendar months, and finally the remaining calendar days in the destination month.

Calendar Day Totals

Total days are calculated through UTC midnight timestamps, accounting for every 365-day year and 366-day leap year along the way.

February 29 Leap Day Policy

If your special date falls on February 29, in non-leap years the anniversary is officially recognized on February 28 (or March 1 according to personal preference).

Traditional & Modern Wedding Anniversary Gifts by Year

Customary US & UK lists

While anniversary traditions vary by culture and historical source, these represent the most widely recognized customary and modern materials.

Anniversary	Traditional Gift	Modern Gift	Flower	Gemstone / Color
1 Year	Paper	Clocks	Carnation	Gold / Peridot
2 Year	Cotton	China	Cosmos	Garnet
3 Year	Leather	Crystal / Glass	Sunflower	Pearl
4 Year	Fruit & Flowers	Electrical Appliances	Hydrangea	Blue Topaz
5 Year	Wood	Silverware	Daisy	Sapphire
6 Year	Candy / Iron	Wood	Calla Lily	Amethyst
7 Year	Wool / Copper	Desk Sets	Freesia	Onyx
8 Year	Bronze / Pottery	Linen / Lace	Lilac	Tourmaline
9 Year	Willow / Pottery	Leather	Bird of Paradise	Lapis Lazuli
10 Year	Tin / Aluminum	Diamond Jewelry	Daffodil	Diamond
11 Year	Steel	Fashion Jewelry	Morning Glory	Turquoise
12 Year	Silk / Linen	Pearls	Peony	Jade
13 Year	Lace	Textiles / Furs	Chrysanthemum	Citrine
14 Year	Ivory (Alternative: Animal Themed)	Gold Jewelry	Dahlia	Opal
15 Year	Crystal	Watches	Rose	Ruby
20 Year	China	Platinum	Aster	Emerald
25 Year	Silver	Silver	Iris	Silver
30 Year	Pearl	Diamond	Lily	Pearl
35 Year	Coral	Jade	African Violet	Emerald
40 Year	Ruby	Ruby	Gladiolus	Ruby
45 Year	Sapphire	Sapphire	Blue Iris	Sapphire
50 Year	Gold	Gold	Yellow Rose / Violet	Gold
55 Year	Emerald	Emerald	Orchid	Emerald
60 Year	Diamond	Diamond	Orchid	Diamond

How to Calculate Your Anniversary and Next Milestone

Get your anniversary breakdown in three simple steps.

Enter your start date

Select your wedding date, first date, or work start date in the date picker.

Verify calculation date

The calculator defaults to today. Change it to calculate your duration for any past or future date.

View results & upcoming milestones

Instantly view your elapsed duration in years, months, and days, total calendar days, your next anniversary date, and key milestone dates.

Frequently Asked Questions

How do you calculate years, months, and days?: We use direct calendar arithmetic. First, full elapsed calendar years are determined from your start date. Then, remaining whole calendar months are counted. Finally, the remaining calendar days between the last month anchor and the calculation date are totaled.
When is a 6-month or half anniversary?: A 6-month anniversary falls exactly six calendar months after your start date (for example, January 15 to July 15). If the start date is on the 31st and the 6-month mark falls in a month with fewer days, the date automatically adjusts to the last day of that month.
How does the calculator handle February 29 (Leap Day) anniversaries?: In leap years, the anniversary falls on February 29. In common non-leap years (which have only 28 days in February), our tool deterministically marks the calendar anniversary on February 28, with a clear note that some couples also choose to celebrate on March 1.
What are day milestones like 100 days or 1,000 days?: Day milestones celebrate round numbers of total days together. Popular relationship milestones include 100 days, 500 days, 1,000 days, and 10,000 days. Our calculator lists these dates chronologically.
Can I use this for work service or memorial dates?: Yes. Simply enter the start date of employment, founding date of a project, or memorial date. The optional occasion selector adjusts the summary phrasing accordingly.