Overview
Use this calculator to find the date that falls a chosen number of days later, such as a delivery deadline, notice period or appointment. It shows the new date and weekday.
Formula
Add the number of days to the start date in the Gregorian calendar, rolling automatically across months and years.
How it works
Pick the start date
The date you are counting from.
Enter the number of days
Any whole number of days can be added.
Read the new date
The resulting date and weekday appear instantly.
Worked examples
A 30-day notice
Adding 30 days to January 1, 2026 gives January 31, 2026.
Two weeks later
Adding 14 days to March 15, 2026 gives March 29, 2026.
Frequently asked questions
Is the start date counted?
No. The result is the start date plus the number of days, with no extra day.
What if I enter zero?
The date stays the same and the result equals the start date.
Does it handle leap years?
Yes, February 29 is included automatically when the range crosses it.
This calculator is for educational and informational purposes only and is not a substitute for professional advice.