Add Days to Date
Calculate a future or past date by adding or subtracting days.
Optionally count only business days, excluding weekends and holidays.
December 8, 2025Monday
December 8, 2025Monday
Options
How to Add Days to a Date
Use this calculator to find what date it will be after adding a specific number of days to any start date. This is useful for calculating deadlines, planning events, or determining delivery dates.
Adding Business Days
When you need to add only business days (excluding weekends and holidays), enable the "Exclude weekends" option. This is particularly useful for legal deadlines, payment processing timelines, shipping and delivery estimates, and project milestone calculations.
Common Calculations
Commonly used for payment terms (Net 30) and short-term planning.
Often used for quarterly planning and warranty periods.
Half-year planning, visa validity checks.
Annual renewals, subscriptions, and contracts.
Subtracting Days
Switch to "Subtract Days" mode to find a past date. This is useful for determining when something started based on how long it's been going, or for calculating backdated deadlines.
Frequently Asked Questions
By default, the calculator counts the days between the two dates, excluding both the start and end dates. If you want to include the end date in your count (adding one extra day), simply toggle on the "Include end date" option in the settings panel. This is important for contracts and legal deadlines where the last day counts.
To manually calculate the number of days between two dates, subtract the earlier date from the later date. For example, days between January 1 and January 15 is 14 days (15 - 1 = 14). However, for business days or dates spanning multiple months, using our date difference calculator is much easier and more accurate.
Business days (also called working days) are calculated by excluding weekends (Saturday and Sunday by default) from the total count. You can customize which days are considered weekends to match different cultural or business practices. Additionally, you can exclude public holidays by selecting your country and optionally a state/province for accurate business days between two dates.
A regular year has 365 days, while a leap year has 366 days. Leap years occur every 4 years (with some exceptions for century years). Our calculator automatically accounts for leap years when calculating the number of days between dates, ensuring February has 29 days in leap years.
In Excel, you can calculate days between dates using a simple formula: =B1-A1 where A1 is the start date and B1 is the end date. For business days, use =NETWORKDAYS(A1,B1). However, Excel's NETWORKDAYS doesn't account for country-specific holidays. Our online calculator supports holidays for 20+ countries with regional variations.
We support public holidays for over 20 countries including the United States, Canada, United Kingdom, Australia, Germany, France, Spain, Italy, Netherlands, Belgium, Switzerland, Austria, Ireland, New Zealand, Sweden, Norway, Denmark, Finland, Singapore, and Japan. For countries with regional holidays (like US states), you can select a specific region.
Yes! Our date calculator shows the time between two dates in multiple formats including total days, weeks, months, and a breakdown of years, months, and days. This is helpful for understanding the duration in different units for project planning or milestone tracking.
Switch to "Add Days" mode using the tabs at the top. Enter your start date and the number of days you want to add. The calculator will show you the resulting date, taking into account your settings for weekends and holidays if enabled. This is useful for calculating deadlines like "30 days from today" or "90 business days from now".