Period Calculator
Calculate time periods between dates with precision. Get exact durations in days, weeks, months, and years.
Understanding Time Periods
Our Period Calculator is a versatile tool for computing the exact duration between two dates. Whether you're planning projects, tracking time intervals, or calculating ages, this calculator provides accurate results in various time units with detailed visualizations.
Different Ways to Measure Time
Calendar Days
Calendar days count every day between the two dates, including weekends and holidays. This is the standard measure for most purposes.
Example: From January 1 to January 31 is 30 days (or 31 days if you include the end date).
Business Days
Business days count only Monday through Friday, excluding weekends. You can also choose to exclude holidays for work schedule calculations.
Example: A 7-calendar-day period might contain only 5 business days if it includes a weekend.
Common Applications:
- Project Planning: Calculate deadlines and timeframes for project milestones
- Age Calculation: Determine precise age in years, months, and days
- Financial Planning: Calculate loan terms, interest periods, or payment intervals
- Event Planning: Determine countdown durations to important dates
- Pregnancy Due Date: Calculate gestation periods and expected delivery dates
- Education: Calculate school terms, semesters, or study periods
- History: Determine time spans between historical events
- Legal Calculations: Calculate legal deadlines, statute limitations, or contract periods
Tips for Using the Period Calculator:
- Include End Date: Toggle this option to count the end date as part of the total period (inclusive counting)
- Include Holidays: When calculating business days, you can choose whether to count holidays as business days
- Custom Units: For specialized calculations, use alternative time units like hours, minutes, seconds, quarters, or decades
- Calendar View: Visualize the period with our interactive calendar to better understand the time span
- Date Formats: Select your preferred date format for clearer understanding of the results
Did You Know?
The length of a month can vary between 28 and 31 days, which means calculations involving months are not always straightforward. Our calculator handles these complexities automatically to give you accurate results.
Frequently Asked Questions
Does the period calculator count the end date?
By default, the calculator counts days from the start date up to but not including the end date. However, you can check the "Include End Date" option to include the end date in your calculation.
How do business days differ from calendar days?
Business days count only Monday through Friday, excluding weekends. When you select the "Business Days" calculation type, our calculator automatically excludes Saturdays and Sundays. You can also choose to exclude holidays using the "Include Holidays" option.
What holidays are excluded in business day calculations?
Our calculator recognizes major US federal holidays including New Year's Day, Martin Luther King Jr. Day, Presidents' Day, Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving Day, and Christmas Day.
Can I calculate time periods in hours or minutes?
Yes! Select "Custom Units" from the Calculation Type dropdown, then choose your desired unit (hours, minutes, seconds, quarters, or decades) from the Custom Unit dropdown.