Dates & time
Date Difference Calculator
Count elapsed days, full weeks and days remaining. This free date difference calculator shows the calculation and its assumptions so you can compare your own figures.
Your results
Count elapsed days, full weeks and days remaining.
Calculated outcomes
- Signed Days
- 87
- Full Weeks
- 12
- Remaining Days
- 3
- Days Since End
- 0
- Direction
- End follows start
Assumptions and estimates
- Calendar dates are compared at UTC midnight, avoiding daylight-saving errors. Elapsed days exclude the start date; no timestamp or partial-day calculation is implied. Countdown uses the entered comparison date, or today in UTC.
- Method: ISO calendar dates are compared using UTC midnight to avoid daylight-saving-hour errors.
- Elapsed days excludes the starting instant. Reverse dates produce a signed difference. The countdown reference date starts at your local calendar date and is refreshed on reset; it remains editable.
Useful next steps
- Use Compare options to test an alternative side by side.
- Copy, print or download a record of this calculation when you need one.
Reports open your email app addressed to s@s1.ie with the public page address only. Your inputs are never added.
How the exact date difference calculation works
ISO calendar dates are compared using UTC midnight to avoid daylight-saving-hour errors.
Elapsed days excludes the starting instant. Reverse dates produce a signed difference. The countdown reference date starts at your local calendar date and is refreshed on reset; it remains editable.
Using this calculator
- Enter your own figures in the labelled inputs. Keep the currencies, units and time periods consistent.
- Choose any applicable rate profile, pattern or assumption shown for this tool. Open additional inputs when relevant.
- Review total days and days until end, then read the stated assumptions and eligibility conditions before using the result.
Worked example
This is a static example using illustrative inputs, not facts about you or today’s date. The displayed eligibility selections and assumptions apply only to this example.
See example inputs
- Start date
- 2026-10-05
- End date
- 2026-12-31
- Countdown reference date
- 2026-10-05
- Total Days
- 87
- Days Until End
- 87