Tool 1: Count the days between two dates
Tool 2: Add or subtract time from a date
How to Use This Calculator
This calculator gives you two easy tools. One counts the exact days between dates. The other adds or subtracts time to find a new date. Pick the tool you need and enter your details.
Tool 2: Add or subtract time from a date.
For Tool 2, just pick your starting date.
Then type the years, months, weeks, or days into the boxes.
Your final answer updates right below the boxes automatically.
Tip: Don't worry about leap years or short months. The calculator handles all that tricky calendar math for you.
Days Calculator Questions
Pick a start date and an end date. The calculator counts every calendar day between them and handles leap years automatically, so the result stays accurate even across February 29.
Yes. Choose a base date, then enter how many days to add or subtract. The tool will show the exact resulting date on the calendar.
Yes. It follows the Gregorian calendar leap-year rules, so date differences and date shifting remain correct across multi-year ranges.
Total days include every day on the calendar. Business days usually mean Monday to Friday and skip weekends. Use business days when you care about working schedules, shipping, or office timelines.
Open Days Until a Date, select August 13 (and the year you mean), and the calculator will show how many days are left from today.
Use Days Since a Date, pick September 30 in the correct year, and you will see exactly how many days have passed since then.
Choose Days Ago, enter 2015, and the tool will return the exact calendar date that is 2015 days before the current date.
Go to Days Until a Date, select September 17 for the year you want, and the calculator will show the remaining day count.