How It Works
Pick your relationship start date and, if you want, an end date. Leave the end date blank to measure up to today, or fill it in to see how long a past relationship lasted.
The calculator finds the exact years, months and days between the two dates, then converts the total day count into weeks, months, hours, seasons and a few fun extras.
Milestones it tracks
Your day count is checked against 13 milestones, from 100 days to 50 years. You will see the last one you reached and a countdown to the next two.
Fun extras
- Shared heartbeats: at 72 beats per minute for each of you.
- Seasons together: one for every 91.25 days.
- Sunrises: one per day together.
- Shared meals: estimated at 1.5 per day.
What Is the Formula?
- Hours = total days × 24.
- Weeks = ⌊total days ÷ 7⌋.
- Months = Y × 12 + M.
- Seasons = ⌊total days ÷ 91.25⌋.
- Heartbeats = total days × 103,680 × 2, since 72 × 60 × 24 = 103,680 beats per person per day.
If the day count goes negative, the calculator borrows the number of days in the previous month, just as you would when subtracting dates by hand.
Relationship Milestones in Days, Months and Years
Use this chart to see how day count milestones compare with months and years.
| Milestone | Days | ≈ Weeks | ≈ Months | ≈ Years |
|---|---|---|---|---|
| 100 days | 100 | 14.3 | 3.3 | 0.27 |
| 6 months | 183 | 26.1 | 6.0 | 0.50 |
| 1 year | 365 | 52.1 | 12.0 | 1.00 |
| 500 days | 500 | 71.4 | 16.4 | 1.37 |
| 2 years | 730 | 104.3 | 24.0 | 2.00 |
| 1,000 days | 1,000 | 142.9 | 32.9 | 2.74 |
| 5 years | 1,825 | 260.7 | 60.0 | 5.00 |
| 2,500 days | 2,500 | 357.1 | 82.1 | 6.84 |
| 10 years | 3,650 | 521.4 | 119.9 | 9.99 |
| 5,000 days | 5,000 | 714.3 | 164.3 | 13.69 |
| 25 years (silver) | 9,125 | 1,303.6 | 299.8 | 24.98 |
| 10,000 days | 10,000 | 1,428.6 | 328.5 | 27.38 |
| 50 years (gold) | 18,250 | 2,607.1 | 599.5 | 49.97 |
Months use an average of 30.44 days. Year milestones use 365 day years, so they can arrive a day or two before the calendar anniversary when leap days fall in between.
Worked Example
A couple got together on 14 February 2022 and checks the calculator on 1 January 2026.
- Start with the raw differences: years 2026 minus 2022 = 4, months January minus February = negative 1, days 1 minus 14 = negative 13.
- Days are negative, so borrow December's 31 days: negative 13 + 31 = 18, and months drop to negative 2.
- Months are negative, so borrow a year: negative 2 + 12 = 10, and years drop to 3.
- Result: 3 years, 10 months and 18 days, or 1,417 days in total.
- That is 34,008 hours, 202 weeks, 46 months and 15 seasons.
- Shared heartbeats: 1,417 × 103,680 × 2 = 293,829,120, shown as 293.8M.
Their last milestone was 1,000 days. The next is 5 years (1,825 days), which is 408 days away, followed by 2,500 days in 1,083 days.