1. What is Week Calculation?

Week calculation determines the number of complete weeks between two dates. It's commonly used in project planning, pregnancy tracking, and various scheduling applications.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• To Date — The end date of the period
• From Date — The start date of the period
• floor() — Rounds down to the nearest integer

Explanation: The calculator first calculates the total days between dates, then divides by 7 (days in a week) and rounds down to get complete weeks.

3. Importance of Week Calculation

Details: Accurate week calculation is essential for project timelines, medical applications (like pregnancy tracking), academic schedules, and financial planning.

4. Using the Calculator

Tips: Enter valid dates in the format YYYY-MM-DD. The "To Date" should be equal to or later than the "From Date" for meaningful results.

5. Frequently Asked Questions (FAQ)

Q1: Does this count partial weeks?
A: No, it only counts complete weeks. Any remaining days after complete weeks are not counted.

Q2: How is this different from calendar weeks?
A: This calculates elapsed time in weeks, not the number of calendar weeks spanned (which would count each Sunday-to-Saturday period).

Q3: What if my dates span a leap year?
A: The calculation automatically accounts for leap years in the day count.

Q4: Can I calculate weeks in the future?
A: Yes, as long as the "To Date" is after the "From Date", it will calculate weeks between them.

Q5: What's the maximum date range this can handle?
A: The calculator can handle any valid date range that PHP's DateTime can process (typically year 0 to 9999).