Debugging Tips When gmdate Outputs Incorrect or Malformed Data

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<p><hr></p>
<p><h2>Debugging Tips When <code>gmdate

Debugging method: Refer to the official PHP documentation to ensure all format characters are correct.

3. Verify PHP timezone settings

Although gmdate uses UTC, timezone settings can affect certain operations during debugging or create confusion when compared with date().

echo date_default_timezone_get(); // Check current timezone
date_default_timezone_set('UTC'); // Explicitly set UTC

4. Validate timestamps using time() or strtotime()

For complex expressions, break down and verify each part individually.

$time = strtotime('2025-08-28 12:00:00');
var_dump($time); // Check the timestamp
echo gmdate('Y-m-d H:i:s', $time);

5. Output raw timestamps for comparison

Sometimes the output seems incorrect, but the issue lies in the timestamp itself. Print the integer value first:

$timestamp = 0;
echo $timestamp; // 0 represents 1970-01-01 00:00:00 UTC
echo gmdate('Y-m-d H:i:s', $timestamp);

6. Enable error reporting

PHP error messages can provide critical clues:

error_reporting(E_ALL);
ini_set('display_errors', 1);

Summary

When encountering unexpected or malformed gmdate output, focus on three main areas:

• Verify the validity of the timestamp
• Check that the format string is correct
• Check timezone settings and enable error reporting if necessary

By incrementally breaking down the code and printing debug information, most gmdate issues can be quickly identified and resolved.