1 var year = 2016; //年份  2 var days = 170; //第几天  3 var reminder = 0;  4   5 function days2month_day(year, days) {  6     "use strict";  7     var month = "1月"; //默认1月  8     var day = "1日";  9     //闰年 1月31  2月29 3月31 4月30 5月31 6月30 7月31 8月31 9月30 10月31 11月30 12月31 10     if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0)) { 11  12         if (days - 31 <= 0) { 13             month = "1月"; 14             reminder = 31 - days; 15             day = "" + reminder + "日"; 16         } else if (days - 60 <= 0) { 17             month = "2月"; 18             reminder = 29 - (days - 31); 19             day = "" + reminder + "日"; 20  21         } else if (days - 91 <= 0) { 22             month = "3月"; 23             reminder = 31 - (days - 60); 24             day = "" + reminder + "日"; 25         } else if (days - 121 <= 0) { 26             month = "4月"; 27             reminder = 30 - (days - 91); 28             day = "" + reminder + "日"; 29  30         } else if (days - 152 <= 0) { 31             month = "5月"; 32             reminder = 31 - (days - 121); 33             day = "" + reminder + "日"; 34  35         } else if (days - 182 <= 0) { 36             month = "6月"; 37             reminder = 30 - (days - 152); 38             day = "" + reminder + "日"; 39  40         } else if (days - 213 <= 0) { 41             month = "7月"; 42             reminder = 31 - (days - 182); 43             day = "" + reminder + "日"; 44  45         } else if (days - 244 <= 0) { 46             month = "8月"; 47             reminder = 31 - (days - 213); 48             day = "" + reminder + "日"; 49  50         } else if (days - 274 <= 0) { 51             month = "9月"; 52             reminder = 30 - (days - 244); 53             day = "" + reminder + "日"; 54  55         } else if (days - 305 <= 0) { 56             month = "10月"; 57             reminder = 31 - (days - 274); 58             day = "" + reminder + "日"; 59  60         } else if (days - 335 <= 0) { 61             month = "11月"; 62             reminder = 30 - (days - 305); 63             day = "" + reminder + "日"; 64  65         } else if (days - 366 <= 0) { 66             month = "12月"; 67             reminder = 31 - (days - 335); 68             day = "" + reminder + "日"; 69         } 70  71  72     } 73     else { 74         //平年 2月28天 75         if (days - 31 <= 0) { 76             month = "1月"; 77             reminder = 31 - days; 78             day = "" + reminder + "日"; 79         } else if (days - 59 <= 0) { 80             month = "2月"; 81             reminder = 28 - (days - 31); 82             day = "" + reminder + "日"; 83  84         } else if (days - 90 <= 0) { 85             month = "3月"; 86             reminder = 31 - (days - 59); 87             day = "" + reminder + "日"; 88         } else if (days - 120 <= 0) { 89             month = "4月"; 90             reminder = 30 - (days - 90); 91             day = "" + reminder + "日"; 92  93         } else if (days - 151 <= 0) { 94             month = "5月"; 95             reminder = 31 - (days - 120); 96             day = "" + reminder + "日"; 97  98         } else if (days - 181 <= 0) { 99             month = "6月";100             reminder = 30 - (days - 151);101             day = "" + reminder + "日";102 103         } else if (days - 212 <= 0) {104             month = "7月";105             reminder = 31 - (days - 181);106             day = "" + reminder + "日";107 108         } else if (days - 243 <= 0) {109             month = "8月";110             reminder = 31 - (days - 212);111             day = "" + reminder + "日";112 113         } else if (days - 273 <= 0) {114             month = "9月";115             reminder = 30 - (days - 243);116             day = "" + reminder + "日";117 118         } else if (days - 304 <= 0) {119             month = "10月";120             reminder = 31 - (days - 273);121             day = "" + reminder + "日";122 123         } else if (days - 334 <= 0) {124             month = "11月";125             reminder = 30 - (days - 304);126             day = "" + reminder + "日";127 128         } else if (days - 365 <= 0) {129             month = "12月";130             reminder = 31 - (days - 334);131             day = "" + reminder + "日";132         }133 134 135     }136     return "" + year + "年" + month + day;137 }138 139 var year_month_day = days2month_day(2016, 170);140 console.log(year_month_day);