What best practices should be followed when manipulating timestamps in PHP to ensure accurate results?

When manipulating timestamps in PHP, it is important to ensure that you are using the correct timezone settings to accurately handle date and time calculations. It is recommended to set the default timezone using the `date_default_timezone_set()` function to avoid any discrepancies. Additionally, using PHP's `DateTime` class can provide a more reliable and object-oriented approach to working with timestamps.

// Set the default timezone to ensure accurate timestamp manipulation
date_default_timezone_set('America/New_York');

// Create a new DateTime object with the current timestamp
$currentTime = new DateTime();

// Manipulate the timestamp as needed
$currentTime->modify('+1 day');

// Output the modified timestamp
echo $currentTime->format('Y-m-d H:i:s');