Add / Subtract Days Calculator - Date Calculator

Add / Subtract Days Calculator

Calculate dates by adding or subtracting days · With detailed date information

Date Calculator
Select Start Date
Number of Days
Operation
Calculated Date
March 19, 2026
Thursday
Week 12 · Day 78 of 365
Day of Year
78
Week Number
12
Quarter
Q1
Days Left
287
Start Date Mar 9, 2026
Days to Add/Subtract 10
Operation Add Days
Result Date Mar 19, 2026
Quick Add/Subtract
Add Days
Calculate future dates by adding days to any start date.
Subtract Days
Find past dates by subtracting days from any date.
Date Details
Get day of week, week number, quarter, and more.

Frequently Asked Questions

How do I add days to a date?
Select your start date, enter the number of days, choose "Add Days" from the operation dropdown, and click Calculate. The result shows the new date with all details.
How do I subtract days?
Choose your start date, enter the days, select "Subtract Days" from the operation dropdown, and calculate. You'll get the past date instantly.
What date information is provided?
You get the full date, day of week, day of year, week number, quarter, and days remaining in the year.
What is the maximum days I can add?
You can add or subtract up to 9,999 days (about 27 years). The calculator handles all date calculations correctly.
Is this calculator free?
Yes! 100% free. No registration, no hidden costs. Use it as many times as you need.
Does it work on mobile?
Absolutely! Fully responsive and works perfectly on all devices - phones, tablets, and desktop.
date calculator add days subtract days days calculator date addition calendar tool

Add / Subtract Days Calculator - Date Calculator Tool

Our Add / Subtract Days Calculator helps you quickly calculate new dates by adding or subtracting any number of days. Perfect for project planning, event countdowns, contract dates, and more.

Common uses: Calculate due dates, find past or future dates, plan events, track project timelines, determine warranty periods, calculate notice periods, and much more.