? PHP TimeZone Functions

? Quick Overview

PHP TimeZone functions are used to manipulate and set the time zone for date and time operations. They ensure accurate date-time handling across different geographical regions.

? Key Concepts

• date_default_timezone_set() – Sets the default timezone for the script.
• date_default_timezone_get() – Returns the current default timezone.
• DateTimeZone – Represents a timezone.
• timezone_offset_get() – Retrieves offset from UTC in seconds.

? Syntax & Theory

PHP uses the server’s default timezone unless explicitly changed. For predictable results, always set a timezone before working with dates.

// Set and retrieve the default timezone
<?php
date_default_timezone_set("America/New_York");
echo "Current timezone: " . date_default_timezone_get();
echo "<br>";
echo "Current time: " . date("Y-m-d H:i:s");
?>

// Calculate timezone offset from UTC
<?php
$timezone = new DateTimeZone("America/New_York");
$datetime = new DateTime("now", $timezone);
echo "Time zone offset: " . $timezone->getOffset($datetime) . " seconds";
?>

? Interactive Timezone Diagram

? Use Cases

• Global applications with users in different countries
• Scheduling systems and reminders
• Logging events with consistent timestamps
• Handling daylight saving time correctly