Utility Stack
Free date tool
Calculate calendar days, business days, weeks, months, and years between two dates.
Estimated result
The calculator compares the start date and end date at midnight local time, then returns the number of calendar days between them. You can choose whether the end date should be included in the total.
Including the end date is useful when both the first and last day count, such as a trip, event window, or hotel stay count. Leaving it unchecked is useful when you need elapsed days between two dates.
Business days usually mean weekdays, Monday through Friday. This calculator excludes weekends when the business-days option is enabled, but it does not remove federal, state, bank, school, or company holidays.
That distinction matters for contracts, shipping estimates, payroll, government forms, school calendars, and legal deadlines. If a deadline is official or high-stakes, confirm the holiday rules with the organization responsible for the deadline.
Different date questions use different counting rules. Choose the count that matches the decision you are making.
| Count type | What it includes | Best for |
|---|---|---|
| Calendar days | Every day, including weekends | Trips, event windows, subscriptions, age milestones |
| Weekdays | Monday through Friday | Simple work-week estimates without holidays |
| Business days | Weekdays under this tool's setting | Rough project, shipping, invoice, or office planning |
| Official business days | Weekdays minus applicable holidays | Legal, government, bank, school, or company deadlines |
Date difference tools are useful for deadlines, project schedules, invoices, trip planning, age milestones, event countdowns, and checking how many workdays are available before a target date.
They are also helpful for comparing subscription billing windows, counting days until a renewal, estimating time between medical appointments, or checking how long a project phase actually lasted.
Calendar days are the most precise number on this page. Weeks are calculated from the day count, while months and years are approximate because real calendar months have different lengths.
For planning, the approximate month and year values are often enough. For billing, contracts, age rules, or compliance deadlines, rely on the exact dates and the responsible organization's rules.
Inclusive counting is the most common reason a result looks one day different from expected. Turn on "include end date" when both the start and end dates should count as part of the range.
| Use case | Include end date? | Reason |
|---|---|---|
| Trip or event days | Usually yes | The arrival and final day often both count. |
| Elapsed time between dates | Usually no | You are measuring the gap between two midnights. |
| Invoice terms | Depends | Use the wording on the invoice or contract. |
| School or work windows | Depends | Use the calendar or policy that controls the deadline. |
Common mistakes include forgetting whether the end date counts, mixing calendar days with business days, ignoring holidays, or assuming every month has 30 days. The include-end-date checkbox is the first thing to check when the result is off by one day.
This tool does not automatically remove public holidays, company holidays, half-days, local closures, school breaks, or region-specific rules. It also does not decide whether a deadline moves when it falls on a weekend.
For official deadlines, keep the calculator result as a planning estimate and verify the final date with the organization, contract, court, school, carrier, or payroll system involved.