What it means
Length of service is the time from the start date to the last working day, usually written in years, months and days. It is used in experience letters, leave and increment calculations, and end-of-service entitlements.
Steps
- Take the start date and last working day as recorded.
- Decide whether to count the last day. For service it is normally counted, because it was a day worked.
- Calculate years, months and days, or use Date Difference with “Include the end date”.
- If the organisation uses the Hijri calendar, calculate in Hijri, because the result differs.
Example
Started 1 January 2015, last working day 30 June 2026:
| Method | Length |
|---|---|
| Gregorian, last day included | exactly 11 years and 6 months |
| Gregorian, last day excluded | 11 years, 5 months and 29 days |
| Hijri, last day included | 11 years, 10 months and 6 days |
| Total days, last day included | 4,199 |
One day changes the whole shape of the Gregorian result, and the Hijri result is more than four months longer because Hijri years are shorter.
Common mistakes
- Subtracting years only (2026 − 2015 = 11) and ignoring months and days.
- Mixing calendars without converting.
- Treating every month as 30 days.
- Forgetting unpaid leave or breaks that may not count as service under the applicable rules.
Important
This article covers the time span only. Financial entitlements such as end-of-service awards are governed by labour law and employer regulations with their own rules for counting service and pay; check the applicable regulation or authority before relying on any figure. Useful tools: Date Difference, Date Calculator, Working Days.
Last updated: