Date Difference Calculator
Count the days, weeks, months and years between two dates.
Date Calculator
Add or subtract days, weeks, months and years from any date.
Business-day mode uses the days field only — years, months and weeks are ignored.
Resulting date
—
Days from start—
Week number—
Day of year—
Leap year—
Quick Tool Overview
The Date Calculator adds or subtracts days, weeks, months and years from any date and returns the resulting date with the weekday it falls on. A business-days mode skips weekends, which is what contracts and shipping estimates almost always mean by "days".
- What it does
- Adds or subtracts time from a date
- You give it
- A start date and an amount to add or subtract
- You get back
- The resulting date and its weekday
- Best for
- Deadlines, notice periods, contracts and delivery dates
About the Date Calculator
Pick a start date, choose how much time to add or subtract, and get the resulting date along with the weekday it falls on. Days, weeks, months and years can be combined in one calculation.
A business-days mode skips weekends, which is what contracts, notice periods and shipping estimates almost always mean by "days". Month arithmetic is handled the way people expect rather than by adding a fixed number of days: one month after 31 January lands on 28 February, or 29 in a leap year, because there is no 31st. Leap years are handled by real calendar rules throughout.
Key features of the Date Calculator
Business-days mode
Skips weekends, which is what a contract, a notice period or a shipping estimate usually means.
Units combined
Days, weeks, months and years can all be applied in one calculation.
Month arithmetic done properly
One month after 31 January lands on 28 February, or 29 in a leap year, because there is no 31st.
Real leap year rules
Calendar arithmetic throughout, not an approximation based on 365.25 days.
Weekday returned
The day of the week is given with the date, which is usually the next thing you need.
How to use the Date Calculator
-
1
Choose a start date
Pick any date from the calendar. It defaults to today.
-
2
Set the amount to add
Enter days, weeks, months or years, and choose whether to add or subtract.
-
3
Switch on business days
Optional. Counts working days only, skipping Saturdays and Sundays.
Frequently asked questions
You get 28 February, or 29 in a leap year, because February has no 31st. The calculator clamps to the last valid day of the target month, which is the standard convention.
Monday to Friday. Public holidays vary by country and are not included, so check your local calendar if a holiday falls inside your range.
By proper calendar arithmetic. A year is a leap year if it divides by 4, except centuries, unless they divide by 400 — which is why 2000 was a leap year and 1900 was not.
Yes. Choose subtract and enter the notice period to find the date you need to act by.
Reviews of the Date Calculator
What people who use the Date Calculator think of it. Reviews come from visitors and are posted as written.
No ratings yet
Yours would be the first.
- 5 0 reviews rated 5 stars
- 4 0 reviews rated 4 stars
- 3 0 reviews rated 3 stars
- 2 0 reviews rated 2 stars
- 1 0 reviews rated 1 star
0 reviews
Newest first
No reviews yet
Be the first to rate the Date Calculator. It takes half a minute and no account.
Write the first reviewMore calculators
Weight Calculator
Convert weights and work in stones, pounds and ounces.
Ratio Calculator
Simplify ratios, scale them up and share a total by any ratio.
Speed Calculator
Solve speed, distance or time and convert between speed units.
Retirement Calculator
Whether your savings will last, and what closes the gap.
Long Division Calculator
Long division worked out step by step, as you would write it.
Amortization Calculator
Every payment split into principal and interest, with totals.
Heat Index Calculator
Apparent temperature from heat and humidity, with risk levels.