DateTime startDate = new DateTime(2009, 3, 10);
DateTime stopDate = new DateTime(2009, 3, 26);
int interval = 3;

while ((startDate = startDate.AddDays(interval)) <= stopDate)
{
    // do your thing
}

@jacob-sobus和@mquander和@Yogurt不完全正确。如果我需要第二天，我通常等待00:00的时间

    public static IEnumerable<DateTime> EachDay(DateTime from, DateTime thru)
    {
        for (var day = from.Date; day.Date <= thru.Date; day = day.NextDay())
            yield return day;
    }

    public static IEnumerable<DateTime> EachMonth(DateTime from, DateTime thru)
    {
        for (var month = from.Date; month.Date <= thru.Date || month.Year == thru.Year && month.Month == thru.Month; month = month.NextMonth())
            yield return month;
    }

    public static IEnumerable<DateTime> EachYear(DateTime from, DateTime thru)
    {
        for (var year = from.Date; year.Date <= thru.Date || year.Year == thru.Year; year = year.NextYear())
            yield return year;
    }

    public static DateTime NextDay(this DateTime date)
    {
        return date.AddTicks(TimeSpan.TicksPerDay - date.TimeOfDay.Ticks);
    }

    public static DateTime NextMonth(this DateTime date)
    {
        return date.AddTicks(TimeSpan.TicksPerDay * DateTime.DaysInMonth(date.Year, date.Month) - (date.TimeOfDay.Ticks + TimeSpan.TicksPerDay * (date.Day - 1)));
    }

    public static DateTime NextYear(this DateTime date)
    {
        var yearTicks = (new DateTime(date.Year + 1, 1, 1) - new DateTime(date.Year, 1, 1)).Ticks;
        var ticks = (date - new DateTime(date.Year, 1, 1)).Ticks;
        return date.AddTicks(yearTicks - ticks);
    }

    public static IEnumerable<DateTime> EachDayTo(this DateTime dateFrom, DateTime dateTo)
    {
        return EachDay(dateFrom, dateTo);
    }

    public static IEnumerable<DateTime> EachMonthTo(this DateTime dateFrom, DateTime dateTo)
    {
        return EachMonth(dateFrom, dateTo);
    }

    public static IEnumerable<DateTime> EachYearTo(this DateTime dateFrom, DateTime dateTo)
    {
        return EachYear(dateFrom, dateTo);
    }

我在MiscUtil中有一个Range类，你可能会发现它很有用。结合各种扩展方法，你可以做到:

foreach (DateTime date in StartDate.To(EndDate).ExcludeEnd()
                                   .Step(DayInterval.Days())
{
    // Do something with the date
}

(你可能想要也可能不想要排除结尾——我只是想提供它作为一个例子。)

这基本上是现成的(更通用的)mquander解决方案形式。

DateTime startDate = new DateTime(2009, 3, 10);
DateTime stopDate = new DateTime(2009, 3, 26);
int interval = 3;

for (DateTime dateTime=startDate;
     dateTime < stopDate; 
     dateTime += TimeSpan.FromDays(interval))
{

}

一年后，希望它能帮助到某人，

为了更加灵活，这个版本包含了一个谓词。

使用

var today = DateTime.UtcNow;
var birthday = new DateTime(2018, 01, 01);

每天到我生日

var toBirthday = today.RangeTo(birthday);  

每月到我生日，第2步

var toBirthday = today.RangeTo(birthday, x => x.AddMonths(2));

每年我的生日

var toBirthday = today.RangeTo(birthday, x => x.AddYears(1));

使用RangeFrom代替

// same result
var fromToday = birthday.RangeFrom(today);
var toBirthday = today.RangeTo(birthday);

实现

public static class DateTimeExtensions 
{

    public static IEnumerable<DateTime> RangeTo(this DateTime from, DateTime to, Func<DateTime, DateTime> step = null)
    {
        if (step == null)
        {
            step = x => x.AddDays(1);
        }

        while (from < to)
        {
            yield return from;
            from = step(from);
        }
    }

    public static IEnumerable<DateTime> RangeFrom(this DateTime to, DateTime from, Func<DateTime, DateTime> step = null)
    {
        return from.RangeTo(to, step);
    }
}

临时演员

你可以抛出一个异常，如果fromDate > toDate，但我更喜欢返回一个空范围，而不是[]

举个例子，你可以试试

DateTime StartDate = new DateTime(2009, 3, 10);
DateTime EndDate = new DateTime(2009, 3, 26);
int DayInterval = 3;

List<DateTime> dateList = new List<DateTime>();
while (StartDate.AddDays(DayInterval) <= EndDate)
{
   StartDate = StartDate.AddDays(DayInterval);
   dateList.Add(StartDate);
}