PHP

Set a Custom Last-Modified Date in a Gzip File

See more Gzip Examples

This example demonstrates how to use the SetDt method to specify a custom last-modified date and time that will be embedded in a Gzip file.

A CkDateTime object is first initialized with a specific date/time using an RFC 822 formatted string. This date/time is then applied to the Gzip object using SetDt.

When a compression method is called (such as CompressStringToFile), the specified date/time is included in the Gzip metadata. This allows the resulting .gz file to carry a meaningful timestamp rather than using the current system time.

Chilkat2 PHP

<?php

use Chilkat2\DateTime;
use Chilkat2\Gzip;

// This example demonstrates how to set a custom last-modified date/time
// that will be embedded in a Gzip file.

$gzip = new Gzip();
$dt = new DateTime();

// Set the date/time using a timestamp format (ISO 8601 style):
$dt->SetFromTimestamp('2025-11-15T12:45:26-05:00');

// Apply the date/time to the Gzip object:
try {
    $gzip->SetDt($dt);

    // Compress a string so the custom date/time is embedded in the .gz:
    $inputStr = 'Example text for Gzip compression.';
    $gzip->CompressStringToFile($inputStr, 'utf-8', 'output.gz');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Gzip file created with custom last-modified date.\n";