When working with PHP, jddayofweek can help with a specific task: returns a weekday number or weekday name for a Julian day.
This guide shows what jddayofweek does, how to use it in code, and which details you should check before relying on the result.
What Is jddayofweek in PHP?
Returns a weekday number or weekday name for a Julian day.
Usage: The following examples show calls with suitable values. Consult the function parameters described in the examples, especially when optional arguments or extensions are involved.
Example 1: Basic Usage
The first example introduces jddayofweek with a direct PHP expression.
<?php
echo jddayofweek(gregoriantojd(10, 16, 2026), 1);
Observe the value returned or printed by jddayofweek and compare it with the input used in this example.
Example 2: A Different Input or Option
This second example demonstrates another input or condition, so you can compare the behavior with the first example.
<?php
echo jddayofweek(gregoriantojd(10, 16, 2026), 0);
Observe the value returned or printed by jddayofweek and compare it with the input used in this example.
Practical Example
Here is a small scenario illustrating how jddayofweek can fit into application code. Run the example only in an appropriate development environment if it reads files, changes data, starts processes or connects to a service.
<?php
$julianDay = gregoriantojd(12, 25, 2026); echo jddayofweek($julianDay, 2);
Observe the value returned or printed by jddayofweek and compare it with the input used in this example.
Important Behavior and Edge Cases
- Core behavior: Returns a weekday number or weekday name for a Julian day.
- Important limitation: Mode 0 returns an integer with Sunday=0, mode 1 a Gregorian name, and mode 2 an abbreviated name.
- Production use: Check return values and handle failures before acting on the result.
Comparison With Related Functions
| Function or Approach | Difference |
|---|---|
jddayofweek() | Returns a weekday number or weekday name for a Julian day. |
jdmonthname() | Related approach. Its purpose and return value differ; select it when your task matches that operation. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Overlooking a special case of jddayofweek(). | Mode 0 returns an integer with Sunday=0, mode 1 a Gregorian name, and mode 2 an abbreviated name. |
Using jddayofweek() without checking the outcome. | Handle failures and confirm that the output is suitable for the next step. |
Key Takeaways
- Returns a weekday number or weekday name for a Julian day.
- Mode 0 returns an integer with Sunday=0, mode 1 a Gregorian name, and mode 2 an abbreviated name.
- Test the function with relevant inputs before using it in production.
Use jddayofweek when its behavior matches the job you need to complete. For dependable results, consider the input data, returned value and limitations shown above.