Relationship Duration Calculator
Calculate how long you have been together in years, months, days, total days, and weeks. Enter your relationship start date and count to today or another date.
Last updated: July 2026
How long you've been together
Calendar duration
How this duration is calculated
UTC date-only arithmetic keeps the result stable across time zones and daylight-saving transitions.
Only the two dates are needed for this calculation. No names or partner details are requested.
How is relationship duration calculated?
The calculator counts complete calendar months from the relationship start date without passing the selected Count until date. Those months are converted into years and months, then any remaining calendar days are added separately.
This avoids treating every month as 30 days or every year as 365 days. Total elapsed days are calculated independently with UTC date-only arithmetic.
How month-end relationship dates are handled
The calculator uses the same explicit month-end convention as the Months Between Dates Calculator. If the original day number does not exist in a later month, it uses that month's final valid day. January 31, 2026 plus one month is February 28, 2026; January 31, 2024 plus one month is February 29, 2024.
Calendar duration and total days are different views
A relationship duration can be described as 1 year, 2 months, and 5 days while also having one exact total-day count. Calendar units provide a familiar human description; total days show the exact number of elapsed calendar dates between the endpoints.
Leap years and elapsed days
Actual Gregorian calendar arithmetic handles leap years. A range that crosses February 29 includes that date in its total-day count, so years are not approximated as always having 365 days.
Worked examples
Exact two years
July 30, 2024 through July 30, 2026 is 2 years and 730 total elapsed days.
Years, months, and days
January 10, 2025 through March 15, 2026 is 1 year, 2 months, and 5 days. The internal 14-month anchor is March 10, 2026.
Leap-day start
February 29, 2024 plus 12 clamped calendar months is February 28, 2025, producing 1 year and 365 total days.
Month-end start
January 31, 2026 through February 28, 2026 is 1 month under the shared month-end convention.
Short relationship
July 1 through July 11, 2026 is 10 days, or 1 full week + 3 days.
Same date
July 30 through July 30, 2026 is 0 years, 0 months, 0 days, and 0 total elapsed days.
One day
July 30 through July 31, 2026 is 1 elapsed day.
What this calculator does not include
This page calculates elapsed relationship duration only. It does not generate upcoming anniversary or day-milestone lists, countdowns, gifts, compatibility results, partner profiles, social captions, or live hours, minutes, and seconds. Use the related Anniversary Milestone Calculator for milestone-date questions.
Frequently asked questions
How do I calculate how long we have been together?
Enter the relationship start date. The calculator compares it with today or another selected date and displays elapsed years, months, and days.
How many days have we been together?
The result includes the exact number of elapsed calendar days between the two entered dates.
Does the start date count as one full day?
No. This calculator measures elapsed time. The same start and end date is zero elapsed days; the following date is one elapsed day.
Does the calculator handle leap years?
Yes. It uses actual Gregorian calendar dates, including February 29 in leap years.
How are relationships that started on January 31 handled?
When a later month lacks the same day number, the calculator uses that month's last valid day for calendar-month duration.
Can I calculate a past relationship duration?
Yes. Change Count until from today to the relationship's historical end date.