How to use the length of service calculator
Benefit eligibility, vesting schedules, paid time off accrual and severance formulas all turn on how long someone has worked for an employer. Enter a start date and a last day worked and the calculator returns total days, the calendar breakdown in years, months and days, and a decimal year figure. Leave the end date blank to measure service up to today.
In the United States no federal statute requires severance based on length of service, so any payout comes from a contract, a plan governed by the Employee Retirement Income Security Act, a collective bargaining agreement or company policy. Service time does drive statutory rights in two familiar places: 29 U.S.C. section 2611(2)(A) makes an employee eligible for Family and Medical Leave Act leave only after 12 months of employment and 1,250 hours of work in the preceding 12 months, and 29 U.S.C. section 1053 sets minimum vesting schedules for retirement plan benefits, commonly three-year cliff or six-year graded vesting.
Figures reflect September 2026. Employers count breaks in service, unpaid leave and rehires in different ways, so check your plan documents or employee handbook for the exact method that applies to you.
This calculator is for reference only and is not legal advice. Consult a licensed employment attorney or your benefits administrator about your specific situation.
Frequently asked questions
Not under federal law. No federal statute requires severance pay based on years of service, so any entitlement comes from an employment contract, a severance plan governed by ERISA, a collective bargaining agreement or company policy.
Under 29 U.S.C. section 2611(2)(A) an eligible employee must have been employed for at least 12 months and have worked at least 1,250 hours in the previous 12 months for a covered employer. The 12 months do not have to be consecutive.
Anniversary-based milestones such as vesting use calendar years and months, while accrual formulas and prorated payouts are usually computed from a fractional year, so both views are useful.