When to use calendar days
Calendar-day counts are useful for travel planning, trial periods, warranty windows, habit tracking and simple countdowns. They include every day unless you choose a different official rule.
📆 Date math
Days Between Dates Calculator
Count calendar days between dates, compare inclusive and exclusive results, and see weekday/weekend context for deadlines, trips, trials, and planning windows.
Free browser utility: Inputs are processed locally in your browser. Results are planning references; confirm payroll, legal, tax, school, or contract deadlines with the relevant official source.
Run the calculator
Formula: end date minus start date = calendar days. Use inclusive mode only when both the first and last day should count.
0 days
Choose dates to calculate.
When weekdays matter
For payroll, service-level agreements, business deadlines, court dates or school schedules, weekday counts are only a starting point. Confirm holiday and jurisdiction rules before acting.
Related time and date tools
FAQ
What is the difference between exclusive and inclusive day counting?
Exclusive counting treats the start date as day zero and does not count the end date. Inclusive counting adds one day when both boundary dates should count.
Does the calculator subtract holidays?
No. It separates weekdays and weekends only. Use an official holiday calendar when a legal, school, or payroll deadline depends on holidays.
Can I calculate dates in the past?
Yes. If the end date is before the start date, the result is shown as a negative day span.
Source snapshot: built from Omellody GSC/local proxy opportunity work, no external keyword-volume or tool-score claims. Formula and browser behavior reviewed 2026-05-19. Deployment changes are not judged in GSC until coverage reaches this date.