Add / Subtract Days
from a Date
Add or subtract days, weeks, or months from any start date to find a new date.
Date Math Calculator
Day of Week
Week Number
Day of Year
Quarter
How to Add Days to a Date
Enter your start date, choose whether to add or subtract, enter the number of days (or weeks, months, or years), then click calculate. The result shows you the exact new date along with what day of the week it falls on, the week number, and the day of the year.