php中日期时间比较三个函数_PHP教程

function compare_date_time( $DATE_TIME1, $DATE_TIME2 )
{
        if ( $DATE_TIME1 == NULL || strlen( $DATE_TIME1 ) == 0 || $DATE_TIME2 == NULL || strlen( $DATE_TIME2 ) == 0 )
        {
                return -1;
        }
        $DATE_TIME1_ARRY = explode( " ", $DATE_TIME1 );
        $DATE_TIME2_ARRY = explode( " ", $DATE_TIME2 );
        if ( compare_date( $DATE_TIME1_ARRY[0], $DATE_TIME2_ARRY[0] ) == 1 )
        {
                return 1;
        }
        if ( compare_date( $DATE_TIME1_ARRY[0], $DATE_TIME2_ARRY[0] ) == 0 )
        {
                if ( compare_time( $DATE_TIME1_ARRY[1], $DATE_TIME2_ARRY[1] ) == 1 )
                {
                        return 1;
                }
                if ( compare_time( $DATE_TIME1_ARRY[1], $DATE_TIME2_ARRY[1] ) == 0 )
                {
                        return 0;
                }
                return -1;
        }
        return -1;
}