Period Duration
A date span shown as combined years, months and days.
About Period Duration
The duration breaks into completed years, remaining months and leftover days since the final year's matching date. A year-month-day breakdown is the clearest way to state long durations like warranties or loans.
Formula
Period Duration
Span = completed years, then months and days since the last matching day
- matching day
- The anniversary day position within the end month
Worked example
With the default values below, Period Duration returns Years of 10. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Start year
- 2,015
- Start monthaccepts 1–12
- 3
- Start dayaccepts 1–31
- 20
- End year
- 2,025
- End monthaccepts 1–12
- 7
- End dayaccepts 1–31
- 10
Results
- Years
- 10
- Months
- 3
- Days
- 20
Step by step
- 1Values used
- 2Period Duration
- 3Years= 10
- 4Months= 3
- 5Days= 20
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Period Duration calculated?
Span = completed years, then months and days since the last matching day The duration breaks into completed years, remaining months and leftover days since the final year's matching date.
Why does Period Duration matter?
A year-month-day breakdown is the clearest way to state long durations like warranties or loans.
What values do I need to enter?
This calculator takes 6 inputs: Start year, Start month, Start day, End year, End month, End day. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.