獲取當前月份的前後幾月

//獲取當前月份的前後幾月
	function GetMonth($sign)  
	{  
		//得到系統的年月  
		$tmp_date=date("Ym");  
		//切割出年份  
		$tmp_year=substr($tmp_date,0,4);  
		//切割出月份  
		$tmp_mon =substr($tmp_date,4,2);  
		// 得到當前月份的下幾月
		//$tmp_nextmonth=mktime(0,0,0,$tmp_mon+$sign,1,$tmp_year);  
		// 得到當前月份的前幾月
		$array = [];
		for($i=$sign-1;$i>=0;$i--){
			$tmp_forwardmonth=mktime(0,0,0,$tmp_mon-$i,1,$tmp_year);
			$array[] = date("m",$tmp_forwardmonth); 
			}
			//$tmp_forwardmonth=mktime(0,0,0,$tmp_mon-$sign,1,$tmp_year);  
		   // return $fm_next_month=date("Ym",$tmp_forwardmonth);  
			return $array;	   
	}