PHP IntlTimeZone::getOffset() Method: Usage and Examples

When working with PHP, you may need to calculate raw and daylight-saving offsets at a specific instant. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.

IntlTimeZone::getOffset: IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.

What Is IntlTimeZone::getOffset in PHP?

Calculate raw and daylight-saving offsets at a specific instant. IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.

Syntax:

$zone->getOffset(...)

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: The timestamp argument is milliseconds. Two by-reference integer variables receive raw and daylight-saving offsets; their sum is the total offset.

Example 1: Basic Usage

This example introduces the operation with a short and predictable input.

<?php

$zone = IntlTimeZone::createTimeZone("Europe/Paris");
$rawOffset = 0;
$daylightOffset = 0;
$zone->getOffset(0, false, $rawOffset, $daylightOffset);
echo ($rawOffset + $daylightOffset) / 3600000;

The code focuses on the main operation. IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.

Example 2: Another Case

Now compare a different input, locale, date, or option to see another part of the behavior.

<?php

$zone = IntlTimeZone::createTimeZone("Europe/Paris");
$rawOffset = 0;
$daylightOffset = 0;
$zone->getOffset(1720000000000, false, $rawOffset, $daylightOffset);
var_dump([$rawOffset, $daylightOffset]);

What changes? The timestamp argument is milliseconds. Two by-reference integer variables receive raw and daylight-saving offsets; their sum is the total offset.

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

$zone = IntlTimeZone::createTimeZone("Europe/Paris");
$timestampMilliseconds = strtotime("2026-07-01 12:00:00 UTC") * 1000;
$raw = 0;
$daylight = 0;
$zone->getOffset($timestampMilliseconds, false, $raw, $daylight);
printf("UTC offset: %.1f hours", ($raw + $daylight) / 3600000);

The practical example demonstrates how to apply this operation to multiple values, a reusable task, or a validated input. IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.

Important Behavior and Edge Cases

• Core behavior: IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.
• Inputs and results: The timestamp argument is milliseconds. Two by-reference integer variables receive raw and daylight-saving offsets; their sum is the total offset.
• Alternatives: DateTimeZone offers the native PHP time-zone API, while IntlTimeZone uses ICU.
• Compatibility: The intl extension is required.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• IntlTimeZone::getOffset helps you calculate raw and daylight-saving offsets at a specific instant.
• IntlTimeZone represents ICU time-zone rules. Offsets are measured in milliseconds rather than seconds.
• The timestamp argument is milliseconds. Two by-reference integer variables receive raw and daylight-saving offsets; their sum is the total offset.

Use IntlTimeZone::getOffset when you need to calculate raw and daylight-saving offsets at a specific instant. 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.