\WP_Stager_Integration\Calendar::calculate_local_timestamp(string $date_string): int

Full Code

/**
 * Calculates a timestamp in the current site's timezone for a date string. Takes the site's timezone setting into account.
 *
 * @param string    $date_string    The date string (formatted as <code>'Y-m-d H:i:s'</code>)
 *
 * @return int  The Unix timestamp for the passed date string in the current site's timezone
 *
 * @see \WP_Stager_Integration\Calendar::calculate_offset_timestamp() for more information on the offset parameter.
 */
public static function calculate_local_timestamp( $date_string ) {

    // Type casting
    $date_string = (string) $date_string;

    // Normalize date string
    $date_string = (string) (\WP_Stager_Integration\Utility::normalize_datetime_string( $date_string ) ?: '');

    // Bail if no date string
    if ( '' === $date_string ) {
        return 0;
    }

    // Instantiate DateTime object in the site's timezone
    $date_time = new \DateTime( $date_string, wp_timezone() );

    return $date_time->getTimestamp();
}