Length of service – seniority, tenure, time in the job – is counted like an age: whole years first, then months, then the days left over. From March 1, 2018 to November 6, 2026 is 8 years, 8 months and 5 days: 104 months, or 3,172 days. Enter your start date and today or an end date, and the calculator gives the length of service in every form, the date of your next work anniversary and when you will reach the next milestone of 5, 10, 15 or more years.
The same period, written five ways
| Form | Start March 1, 2018, to November 6, 2026 |
|---|---|
| Years, months, days | 8 years, 8 months, 5 days |
| Decimal years | 8.68 years |
| Months | 104 |
| Weeks | 453 weeks and 1 day |
| Days | 3,172 |
CVs and job applications often use years and months; benefit and pension forms may ask for decimal years or days. The last-day option adds one day for rules that count both ends.
How months are counted
A month is counted from a date to the same date in the next month. When that date does not exist, as with a start on January 31, the anniversary falls on the last day of the shorter month. That is how calendars, contracts and most laws count months, and it keeps the anniversaries on the same day each year.
Milestones
Many employers mark 5, 10, 15, 20 and 25 years of service, and some benefits, notice periods or leave allowances change with seniority. The results show the date of your next milestone, so you can see how far away it is. Whatever the rules where you work, the dates themselves are the same everywhere.
The calculator runs in your browser and works offline once the site is saved.
Frequently asked questions
How do I calculate length of service?
Count the whole years and months from the start date, then the days left over, the same way you count an age. From March 1, 2018 to November 6, 2026 is 8 years, 8 months and 5 days.
Should the last day be counted?
Usually not: like an age, a job that starts on March 1 completes its first year on the next March 1. Some payroll and pension rules count both the first and the last day; the calculator has an option that adds the end date.
How do I show length of service in years with decimals?
Divide the total days by 365.2425, the average length of a year in our calendar. 3,172 days is 8.68 years.
When is my next work anniversary?
On the same day and month as your start date. A start on February 29 has its anniversary on February 28 in common years, as calendars and most contracts count it.
Can I count service across two jobs?
Work out each period separately and add the years, months and days. If your employer counts continuous service across a break, its own rules decide.
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