根据年月日计算星期

//根据日期计算星期（日期格式：yyyy-MM-dd) public string WeekDayNoMsg(string dtime) { int y = Convert.ToInt32(dtime.Substring(0, 4)); int m = Convert.ToInt32(dtime.Substring(5, 2)); int d = Convert.ToInt32(dtime.Substring(8, 2)); if (m == 1) m = 13; if (m == 2) m = 14; int week = (d + 2 * m + 3 * (m + 1) / 5 + y + y / 4 - y / 100 + y / 400) % 7; string weekstr = string.Empty; switch (week) { case 0: weekstr = "星期一"; break; case 1: weekstr = "星期二"; break; case 2: weekstr = "星期三"; break; case 3: weekstr = "星期四"; break; case 4: weekstr = "星期五"; break; case 5: weekstr = "星期六"; break; case 6: weekstr = "星期日"; break; } return weekstr; }