Days Calculator: How Many Days Between Two Dates?
Need to know exactly how many days are between two dates? This free days calculator gives you the precise day count instantly — plus the same span broken down into weeks, months, and years. Switch tabs to add or subtract days from any date, or tick the box to count business days only (weekends excluded). Everything runs 100% in your browser — no sign-up, nothing uploaded.
100% client-side — nothing is uploaded or stored. Dates use your device's calendar.
How to use it
Days between dates: pick a start date and an end date — the order doesn't matter. The tool instantly shows the total days, plus the span expressed as weeks (with the leftover days), full calendar months, and years. Tick "Business days only" to exclude Saturdays and Sundays, which is what most people want for work deadlines and delivery estimates.
Add / subtract days: switch to the second tab when you need a date in the future or the past — "what date is 90 days from today?" or "when was 6 weeks ago?". Enter the number of days, choose add or subtract, and you'll get the exact date plus its day of the week.
What it expects
Just valid calendar dates from your browser's date picker — any year your browser supports. If a field is empty or a date can't be parsed, you'll get a friendly message instead of a wrong answer. A few things worth knowing about how the math works:
- Date difference is exclusive of the start day. Monday to Friday counts 4 days (Tue–Fri), matching spreadsheet
DAYS()behavior. Add 1 if you need both endpoints included. - Months are calendar months, not 30-day blocks. The tool counts full months elapsed (e.g. March 10 → May 10 = 2 months) and shows leftover days separately, so anniversaries and billing cycles read correctly.
- Business days skip weekends only. Public holidays vary by country, so they're not excluded automatically — subtract them yourself if one falls inside your range.
- Leap years are handled. February 29 counts whenever it falls inside the range, because the math uses real calendar dates, not 365-day approximations.
Common uses for a days calculator
- Project deadlines: "How many working days do we actually have until launch?" — business-days mode gives the honest number, not the calendar number.
- Age in days: enter a birth date and today to see an age expressed as total days, or years + months + days — a fun stat for birthdays and milestones.
- Event countdowns: weddings, exams, trips, product launches — see the wait as days, then as weeks, to make it feel real.
- Contract and notice periods: "90 days from today" or "30 days before the renewal date" — the add/subtract tab lands on the exact date and tells you which weekday it is.
- Habit and streak tracking: day 1 to today, at a glance — useful for fitness streaks, sobriety counters, and study plans.
Frequently asked questions
- How many days are between two dates?
- Pick the start and end dates above and the calculator shows the exact number of days between them, plus the same span expressed as weeks, months, and years. The order doesn't matter — if you put the later date first, it still gives the same answer. The count is the standard date difference: January 1 to January 2 is 1 day.
- Does the calculator count the start and end dates?
- It counts the days in between, not the starting day itself. So Monday to Friday is 4 days by default (Tuesday, Wednesday, Thursday, Friday). This matches how most date-difference tools and spreadsheet DAYS functions behave. If you need an inclusive count, just add 1 to the result.
- How are business days counted?
- Tick "business days only" and Saturdays and Sundays are excluded from the count — the tool walks through every day in the range and counts only Monday–Friday. Public holidays are not excluded, because they differ by country and region; if a holiday falls in your range, subtract it manually from the result.
- How do I add or subtract days from a date?
- Switch to the "Add / subtract days" tab, pick a start date, enter a number of days, and choose add or subtract. The calculator shows the resulting date along with its day of the week — handy for "what date is 90 days from today?" or "when was 6 weeks ago?"
- Why do months and years show as approximations sometimes?
- Days and weeks are exact, but calendar months vary in length (28–31 days), so any day-count converted to months is a calendar breakdown, not a fixed unit. The tool shows full calendar months elapsed plus the remaining days — for example, March 10 to May 15 is 2 months and 5 days — which is the most useful reading for deadlines and anniversaries.
- Does it handle leap years correctly?
- Yes. The calculation uses your browser's built-in date math, which accounts for leap years automatically — February 29 is included whenever it falls inside your range. A span like March 1, 2023 to March 1, 2024 correctly counts 366 days because it crosses the 2024 leap day.
- Is my date data uploaded anywhere?
- No. All calculations happen in your browser with JavaScript — your dates never leave your device, and there's nothing to sign up for.