About the Days Between Dates Calculator
Calculate the calendar days and weeks between two dates, avoiding daylight-saving timing problems.
Formula or method
Parse date-only inputs into UTC calendar dates and divide the difference in milliseconds by the length of a 24-hour day.
Worked example
The difference between January 1 and January 8 is seven days, or one week.
How to use the tool
Start with the example values above, then replace each input with your own figures. The results update immediately. Review the units, denominators, and assumptions before using any number in an important decision.
Assumptions and limitations
This counts calendar days, not business days. Holidays, time-of-day and local working schedules are not included.
Frequently asked questions
Does the result count the starting day?
No. The difference between the same dates is zero days.
Privacy and support
Your inputs are processed locally in your browser. ToolMosaic does not upload or store the values you enter in this tool. Our tools are free, and we appreciate your support.