The formula
contributed = union of the periods, in days ÷ 365
Where it comes from
A work history is a list of start and end dates, and adding it up by eye goes wrong in two places: periods that overlap — two jobs at once count only once — and years counted as 365 days, which is how any pension administration keeps them. Here the spells are merged, the overlap is taken out, and the total is turned into years, months and days. The years needed to retire are set by each country’s law and are a field, not a figure this site publishes.
How to work it out by hand
- Enter each period with its start and end date
- Merge the ones that touch or overlap into a single spell
- Add up the days in each spell, counting both ends
- Divide by 365 for the years, and subtract from the target to see what is left
What is worth knowing
Overlap is the mistake that inflates the count most: anyone who held two contracts at once, or whose end and start dates cross through a typo, adds months that do not exist. The page says how many days it has taken out for that, and the figure is worth a look: if it is large and you never had two jobs, a date is wrong. And a word on the target: this counts time, not money. Every country has its own rules on which periods count — unemployment, leave, military service, contributions abroad — and on what you get for them; that comes from the pension administration, not from this page.