Days Between Two Dates
To count calendar days between start and end:
- •Exclusive end: don't count the end date
- •Inclusive both: add 1 to the difference
Our calculator clarifies which convention it uses — read the label.
Weeks, Months, Years
Weeks = days ÷ 7 (often remainder days left over).
Months and years are ambiguous when day-of-month differs — Jan 31 + 1 month is not Feb 31. Libraries use calendar arithmetic, not fixed 30-day months.
Business Days
Weekdays excluding weekends and optionally holidays matter for SLAs, contracts, and shipping estimates — holiday calendars vary by country and employer.
A raw date difference calculator may not exclude holidays unless specified.
How to Use This Date Calculator
Pick start and end dates. See days, weeks, and months/years approximations — use for project timelines, deadlines, and travel planning.