Add Days Calculator

Enter today's date as the start date, select 'Add', enter the number of days, and click Calculate. For example, to find the date 90 days from January 15, 2025: start with January 15, add 90 days, and get April 15, 2025. The calculator handles month lengths and leap years automatically.

Calendar days include every day (Monday through Sunday). Business days exclude weekends (Saturday and Sunday), counting only Monday through Friday. For a 10-day deadline: calendar days = 10 actual days; business days = 10 working days, which spans about 14 calendar days. Use business days for work deadlines and payment terms.

Start with the current date or contract start date. Add the deadline period (e.g., 30 days for payment terms, 90 days for a project). The result shows the exact due date and what day of the week it falls on. For business deadlines, enable 'Business Days Only' to exclude weekends from the count.

Adding months moves to the same day number in the target month. If that day doesn't exist (like adding 1 month to January 31), the calculator uses the last day of the target month (February 28 or 29). So January 31 + 1 month = February 28 (or 29 in leap years). This follows standard date math conventions.

Select 'Subtract' instead of 'Add', enter your reference date, and input the number of days. For example, to find what date was 60 days before March 1, 2025: start with March 1, subtract 60 days, and get December 31, 2024. This works for weeks, months, and years too.