Add or subtract days from a date, or calculate the exact duration and days since a specific event.
Resulting Date
Tuesday, August 4th, 2026
Last updated: July 2026
The Ultimate Date Calculator
Whether you need to find out exactly what date it will be 90 days from today, or you want to calculate the exact number of business days between two deadlines, this tool handles all complex date math instantly.
Adding and Subtracting Time
Time mathematics can be tricky because months have different numbers of days and leap years shift the calendar. Our calculator uses precise date-math algorithms to safely add or subtract years, months, weeks, and days without errors.
Example: Starting from March 15, 2026, and adding 90 days lands on June 13, 2026 — the calculator handles the uneven month lengths (31, 30, 31 days) automatically so you don't have to count by hand.
Finding the Days Between Two Dates
The "Days Between" tab gives you two numbers at once: the total calendar days, and the business days (Monday-Friday only). This split matters because a deadline that's "10 days away" can mean very different things depending on how many weekends fall in between.
Example: From a Friday to the following Monday is 3 calendar days apart, but only 1 business day, since the Saturday and Sunday in between are excluded from the business-day count.
Note that this business-day count excludes weekends only, not federal holidays. For payroll, PTO, or SLA deadlines where holidays also need to be excluded, use the dedicated Business Days Calculator or Workdays Calculator instead.
Frequently Asked Questions
It allows you to input any start date and mathematically add or subtract days, weeks, months, or years to find a future or past date.
Yes! Switch to the 'Days Between' tab, enter two dates, and it will instantly give you the total days and business days between them.
Yes, our business day calculation automatically excludes Saturdays and Sundays from the total.
Absolutely. Our mathematical engine fully supports leap years, ensuring day calculations across February are 100% accurate.
No, this tool excludes weekends only. If you need federal holidays excluded too, for example for SLA or shipping deadlines, use our dedicated Business Days Calculator or Workdays Calculator.
It doesn't matter. The calculator automatically sorts the earlier and later date before finding the difference, so you'll always get a positive result.
Yes, use the 'Add / Subtract Dates' tab, set the start date to today, enter 90 in the Days field, and keep the action set to Add.
Yes, set your start date to today and your end date to the deadline in the 'Days Between' tab to see exactly how many total days and business days remain.