What are the potential pitfalls when trying to calculate end dates in PHP using date functions?

When calculating end dates in PHP using date functions, potential pitfalls include not accounting for factors like time zones, daylight saving time changes, or leap years. To ensure accurate end date calculations, it is important to use the appropriate date functions and consider these factors when determining the end date.

// Example code snippet to calculate end date while considering time zone and daylight saving time
$startDate = new DateTime('2022-01-01', new DateTimeZone('America/New_York'));
$interval = new DateInterval('P1M'); // 1 month interval
$endDate = clone $startDate;
$endDate->add($interval);
echo $endDate->format('Y-m-d H:i:s');