What are best practices for handling timestamps in PHP when working with external plugins?

When working with external plugins in PHP, it is important to ensure that timestamps are handled consistently to avoid any conflicts or errors. One best practice is to always convert timestamps to a standardized format, such as Unix timestamp, before passing them to external plugins. This helps ensure that the timestamps are interpreted correctly regardless of the timezone or format used by the plugin.

// Convert timestamp to Unix timestamp before passing to external plugin
$timestamp = strtotime('2022-01-01 12:00:00');
// Pass $timestamp to external plugin for processing