1. What is Duration Calculation?

Duration calculation measures the time between two dates in days. It's useful for project planning, event countdowns, tracking periods between events, and various time-based calculations.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• End Date — The later date in the period
• Start Date — The earlier date in the period

Explanation: The calculation counts all calendar days between the two dates, including the start date but excluding the end date.

3. Importance of Duration Calculation

Details: Accurate duration calculation is essential for project management, rental agreements, medication schedules, legal deadlines, and many other time-sensitive applications.

4. Using the Calculator

Tips: Enter both dates in YYYY-MM-DD format. The end date must be equal to or later than the start date for valid results.

5. Frequently Asked Questions (FAQ)

Q1: Does this include both start and end dates?
A: By default, it includes the start date but excludes the end date in the count (inclusive-exclusive).

Q2: How does it handle leap years?
A: The calculation automatically accounts for leap years in the duration period.

Q3: Can I calculate time periods across BC/AD?
A: This calculator is designed for dates in the Common Era (AD) only.

Q4: What's the maximum date range supported?
A: The calculator can handle any reasonable date range that fits within PHP's DateTime limitations (typically years 0-9999).

Q5: Does it account for time zones?
A: No, this calculator works with calendar dates only without considering time zones.