Returns the number of days in a calendar month.
What Is cal_days_in_month() in PHP?
Returns the number of days in a calendar month.
Its syntax is:
cal_days_in_month(int $calendar, int $month, int $year): intParameters:
$calendar— Accepted as int; required argument.$month— Accepted as int; required argument.$year— Accepted as int; required argument.
Return type: int. Use the appropriate calendar constant. February depends on leap years.
Availability: Requires the calendar extension.
Example 1: Basic Usage
<?php
echo cal_days_in_month(CAL_GREGORIAN, 2, 2024);
Output:
29Use the appropriate calendar constant. February depends on leap years.
Example 2: A Different Input
<?php
echo cal_days_in_month(CAL_GREGORIAN, 4, 2025);
Output:
30Use the appropriate calendar constant. February depends on leap years.
Practical Example: Applying It in a Program
<?php
$months = [2, 4, 12]; foreach ($months as $month) { echo "$month: " . cal_days_in_month(CAL_GREGORIAN, $month, 2025) . PHP_EOL; }
Output:
2: 28
4: 30
12: 31Use the appropriate calendar constant. February depends on leap years.
Important Behavior and Edge Cases
- Key behavior: Use the appropriate calendar constant. February depends on leap years.
- Environment: Requires the calendar extension.
Comparison With Related Functions
| Function | Purpose |
|---|---|
cal_days_in_month() | Returns the number of days in a calendar month. |
date("t") | date("t") returns the days in a month of a PHP date; cal_days_in_month() supports a specified calendar system. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Ignoring this behavior: Use the appropriate calendar constant | Use the appropriate calendar constant. February depends on leap years. |
Key Takeaways
- Returns the number of days in a calendar month.
- Use the appropriate calendar constant. February depends on leap years.
- Requires the calendar extension.
Summary: Use the appropriate calendar constant. February depends on leap years.