source/Core/UtilsDate.php
public function isEmptyDate($sDate)
    {
        if (!empty($sDate)) {
            $sDate = preg_replace("/[^0-9a-z]/i", "", $sDate);
            if (!is_numeric($sDate) || $sDate != 0) {
                return false;
            }
        }

        return true;
    }
public function isEmptyDate($sDate)
    {
        if (!empty($sDate)) {
            $sDate = preg_replace("/[^0-9a-z]/i", "", $sDate);
            if (!is_numeric($sDate) || $sDate != 0) {
                return false;
            }
        }

        return true;
    }
public function isEmptyDate ( $ sDate ) { if ( ! empty ( $ sDate ) ) { $ sDate = preg_replace ( "/[^0-9a-z]/i" , "" , $ sDate ) ; if ( ! is_numeric ( $ sDate ) || $ sDate != 0 ) { return false ; } } return true ; }
Checks if date string is empty date field. Empty string or string with
all date values equal to 0 is treated as empty.

@param array $sDate date or date time string

@return bool
Checks if date string is empty date field . Empty string or string with all date values equal to 0 is treated as empty .