Quick answer
Record the recognised start date and its source, the reference date, the calendar duration, and any adjustment with its reason. Derive the figure; never store it.
Which start date
There is rarely only one. The offer date, the contract date, the first working day, the payroll start and the recognised service date can all differ, and after a TUPE transfer, an acquisition or a rehire there may be an earlier date that carries forward.
Whichever one the record uses, name it and say where it came from. 'Recognised service date 1 March 2012, carried forward from acquisition, per HR file' is auditable. '2012' is not.
Use this guide with the right tool: Open the Work Anniversary Countdown for the next employment anniversary and completed service duration. If the question shifts, compare it with the Employment Duration Calculator or the Service Milestone Calculator.
Duration is derived, not stored
Tenure changes every day. Any system that stores a computed years-of-service figure is storing something that starts going stale immediately and gives no signal when it does.
Store the start date and derive the duration whenever it is displayed. Where a snapshot genuinely must be kept — because it fed a decision on a particular day — store it with that date and label it as historical.
Adjustments belong on separate lines
Unpaid leave, career breaks, casual periods before permanent employment and other exclusions produce credited service that differs from calendar duration. Folding them into a single number destroys the audit trail.
Record the calendar figure, then each adjustment with its reason and the policy that authorised it, then the resulting credited service. Anyone reviewing can follow the arithmetic and see which step they disagree with, if any.
Anniversaries are a separate calculation
A work anniversary is a calendar anniversary of the recognised start date, found by adding whole years. It is not the same as completed credited service, which may be lower, and the two can drift apart after a break in service.
For recognition programmes this matters: an employee's fifth anniversary and their fifth year of credited service can fall in different years. Decide which the programme is based on and say so, because people notice.
Worked example
The example is there to show the shape of the working. Your own dates will behave the same way; the rule that governs them may not.
Common mistakes to avoid
- Recording only a year. Start month and day determine every anniversary and every duration. A year alone is not a start date.
- Storing a computed tenure figure. Store the date and derive the duration, or the record decays silently.
- Merging adjustments into one number. Keep each adjustment on its own line with its reason, or the figure cannot be audited.
Use the right calculator
These are the practical next step. Each opens with the calculator, states its method, and links onward when the question turns out to be a different one.
Frequently asked questions
Which start date should the record use?
The recognised service date under your policy, with its source named. Where several dates exist, record them all.
Do anniversaries and credited service always match?
No. After a break in service they can differ by months or years. Say which one a programme uses.
What is the minimum to record?
Recognised start date and source, reference date, calendar duration, each adjustment with its reason, and the resulting credited service.