Date Difference Calculator
Find the exact number of days, weeks, or months between two dates.
About this tool
Measure the calendar gap between a start date and an end date and view it as days, weeks, months, and years. The day count comes from the elapsed milliseconds divided by 86,400,000, while week, month, and year views provide useful larger-unit comparisons. The displayed units summarize the same interval rather than creating a detailed calendar schedule. From March 1 to March 15, the elapsed gap is 14 days, or 2 weeks. From January 1 to April 1 in a non-leap year, the interval is 90 days, which is about 3 months. Use the calculator to check time until a deadline, length of a trip, project duration, rental period, anniversary gap, or the spacing between appointments. Choose dates in the intended order and calculate. Calendar-day results include weekends and holidays; this is not a business-day counter. If your policy counts both the first and last day, add one to a conventional elapsed-day result. Month and year summaries compare calendar fields and completed month boundaries, while weeks are shown as whole weeks plus remaining days. Consult the governing agreement when billing periods or legal deadlines define their own inclusion rules.
How to use
Pick the earlier or reference day in "Start Date" and the comparison day in "End Date."
Select "Calculate Difference" to measure the interval.
Read the same gap summarized in days, weeks, months, and years.