1. What is Days Calculation?

Days calculation determines the number of days between two dates. This is useful for project planning, financial calculations, medical treatment durations, and many other applications where time intervals need to be measured precisely.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( Date1 \) — The earlier date
• \( Date2 \) — The later date

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

3. Importance of Days Calculation

Details: Accurate day counting is essential for calculating interest, project timelines, medication schedules, legal deadlines, and many other time-sensitive calculations.

4. Using the Calculator

Tips: Enter both dates in YYYY-MM-DD format. The calculator will automatically determine which date is earlier and calculate the days between them.

5. Frequently Asked Questions (FAQ)

Q1: Does this include both start and end dates?
A: By default, the calculation includes the start date but excludes the end date. For inclusive counting, add 1 to the result.

Q2: How are leap years handled?
A: The calculation automatically accounts for leap years and varying month lengths.

Q3: What's the maximum date range?
A: The calculator can handle any valid date range supported by PHP's DateTime class.

Q4: Can I calculate time as well as days?
A: This calculator focuses on whole days. For more precise time calculations, consider a datetime calculator.

Q5: What if I enter dates in the wrong order?
A: The calculator will still give a positive number of days as it automatically determines which date is earlier.