Years of Service Calculator
Enter a hire date (or any start date) to calculate exact years, months, and days of service, along with a countdown to the next anniversary.
Length of service
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Enter a start date to calculate.
How the Years of Service formula works
The same calendar-difference approach used for age calculations:
years = endYear − startYear (adjusted if the anniversary hasn't occurred yet this year) months, days = adjusted similarly, borrowing from the prior month/year as needed
Step-by-step calculation
- Subtract the start date from today's date, component by component (years, months, days).
- Borrow days from the previous month and months from the previous year where needed, matching real calendar lengths.
- Separately calculate the number of days remaining until the next anniversary of the start date.
Worked example
Someone hired on March 10, 2019, checked on July 26, 2026: that's 7 years, 4 months, 16 days of service — with the next anniversary (March 10, 2027) about 7.5 months away.
Frequently asked questions
Can I use this for things besides work anniversaries?
Yes — it works for any starting date you want to track tenure or count anniversaries from, like a membership start date, a relationship anniversary, or time since a move.