When working with PHP, you may need to read the recurrence count provided when the period was created. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.
DatePeriod::getRecurrences: Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
What Is DatePeriod::getRecurrences in PHP?
Read the recurrence count provided when the period was created. Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
Syntax:
$period->getRecurrences(): ?int
Parameters and return value: The signature above identifies the arguments and return type where the API has a single call. For topic guides, follow the sequence of calls in the examples. Always distinguish a returned value from an object or variable modified by reference.
Important: Do not equate getRecurrences() with count(iterator_to_array($period)): start and end inclusion can change the number yielded.
Example 1: Basic Usage
This example introduces the operation with a short and predictable input.
<?php
$period = new DatePeriod(new DateTimeImmutable("2026-01-01"), new DateInterval("P1D"), 3);
var_dump($period->getRecurrences());
Output:
int(3)
The code focuses on the main operation. Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
Example 2: Another Case
Now compare a different input, locale, date, or option to see another part of the behavior.
<?php
$period = new DatePeriod(new DateTimeImmutable("2026-01-01"), new DateInterval("P1D"), new DateTimeImmutable("2026-01-10"));
var_dump($period->getRecurrences());
Output:
NULL
What changes? Do not equate getRecurrences() with count(iterator_to_array($period)): start and end inclusion can change the number yielded.
Practical Example: Applying It in an Application
Use the following separate example as a starting point for a small application task. Check any extension or environment requirements below before running it.
<?php
$start = new DateTimeImmutable("2026-01-01");
$period = new DatePeriod($start, new DateInterval("P1W"), 4);
echo "Configured recurrences: " . ($period->getRecurrences() ?? "not specified");
Output:
Configured recurrences: 4
The practical example demonstrates how to apply this operation to multiple values, a reusable task, or a validated input. Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
Important Behavior and Edge Cases
- Core behavior: Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
- Inputs and results: Do not equate getRecurrences() with count(iterator_to_array($period)): start and end inclusion can change the number yielded.
- Alternatives: DatePeriod::getEndDate() describes date-bounded periods rather than recurrence-bounded ones.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
DatePeriod::getRecurrences | Read the recurrence count provided when the period was created. |
| Related PHP approach | DatePeriod::getEndDate() describes date-bounded periods rather than recurrence-bounded ones. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Using an incorrect input or option | Do not equate getRecurrences() with count(iterator_to_array($period)): start and end inclusion can change the number yielded. |
| Confusing this API with a related operation | DatePeriod::getEndDate() describes date-bounded periods rather than recurrence-bounded ones. |
| Assuming output is identical across environments | Check return values and required extensions or versions. Use explicit locale, timezone or encoding settings when they affect the result. |
Key Takeaways
- DatePeriod::getRecurrences helps you read the recurrence count provided when the period was created.
- Returns an explicitly supplied recurrence count, or null for periods specified with an end date.
- Do not equate getRecurrences() with count(iterator_to_array($period)): start and end inclusion can change the number yielded.
Use DatePeriod::getRecurrences when you need to read the recurrence count provided when the period was created. Start with the first example, compare the second, and adapt the practical example to your inputs. Confirm the return value and environment requirements before adding it to production code.