1 function theWeek(now) { 2     var totalDays = 0; 3     years = now.getYear() 4     if (years < 1000) 5         years += 1900 6     var days = new Array(12); 7     days[0] = 31; 8     days[2] = 31; 9     days[3] = 30;10     days[4] = 31;11     days[5] = 30;12     days[6] = 31;13     days[7] = 31;14     days[8] = 30;15     days[9] = 31;16     days[10] = 30;17     days[11] = 31;18 19     //判断是否为闰年，针对2月的天数进行计算20     if (Math.round(now.getYear() / 4) == now.getYear() / 4) {21         days[1] = 2922     } else {23         days[1] = 2824     }25 26     if (now.getMonth() == 0) {27         totalDays = totalDays + now.getDate();28     } else {29         var curMonth = now.getMonth();30         for (var count = 1; count <= curMonth; count++) {31             totalDays = totalDays + days[count - 1];32         }33         totalDays = totalDays + now.getDate();34     }35     //得到第几周36     var week = Math.round(totalDays / 7);37     return week;38 }