正如我在评论中提到的那样，“下一个星期二”可能意味着多种含义，但是这段代码为您提供了“下一个星期二发生，或者如果今天已经是星期二，则显示为今天”：
DateTime today = DateTime.Today;// The (... + 7) % 7 ensures we end up with a value in the range [0, 6]int daysUntilTuesday = ((int) DayOfWeek.Tuesday - (int) today.DayOfWeek + 7) % 7;DateTime nextTuesday = today.AddDays(daysUntilTuesday);
如果要给“一周的时间”（如果已经是星期二），则可以使用：
// This finds the next Monday (or today if it's Monday) and then adds a day... so the// result is in the range [1-7]int daysUntilTuesday = (((int) DayOfWeek.Monday - (int) today.DayOfWeek + 7) % 7) + 1;
…或者您可以使用原始公式，但是从明天开始：
DateTime tomorrow = DateTime.Today.AddDays(1);// The (... + 7) % 7 ensures we end up with a value in the range [0, 6]int daysUntilTuesday = ((int) DayOfWeek.Tuesday - (int) tomorrow.DayOfWeek + 7) % 7;DateTime nextTuesday = tomorrow.AddDays(daysUntilTuesday);
编辑：只是为了使这个漂亮和通用：
public static DateTime GetNextWeekday(DateTime start, DayOfWeek day){ // The (... + 7) % 7 ensures we end up with a value in the range [0, 6] int daysToAdd = ((int) day - (int) start.DayOfWeek + 7) % 7; return start.AddDays(daysToAdd);}因此，要获取“今天或未来6天”的值：
DateTime nextTuesday = GetNextWeekday(DateTime.Today, DayOfWeek.Tuesday);
获取“下一个星期二（今天除外）”的值：
DateTime nextTuesday = GetNextWeekday(DateTime.Today.AddDays(1), DayOfWeek.Tuesday);
