Getting all DateTimes between two 'DateTime's in C#

Question

I have two DateTimes, and I want to get all DateTimes between these Dates. Such as, if my Dates are like 01.01.2010 - 05.01.2010, my function shoul

Answer 1

You can use DateTime objects directly in the loop, in place of your int. DateTime.AddDays handles month ends correctly.

for (DateTime date = startingDate; date <= endingDate; date = date.AddDays(1))
    allDates.Add(date);

Answer 2

Given a lowerdate value and higher date value in String and a frequency as the third parameter this method should return a dictionary of dates; where the key is the start value of a date range and the value is the respective range. This works fine if the frequency is either weekly or monthly- you can customize it as per your need. The date values passed should be in proper format or you might need to format it using tryParseExact or something like that.

    protected static Dictionary<DateTime, String> getDateRange(String lowerDate, String higherDate, String frequency)
    {
        DateTime startDate, endDate;
        startDate = Convert.ToDateTime(lowerDate);
        endDate = Convert.ToDateTime(higherDate);

        Dictionary<DateTime, String> returnDict = new Dictionary<DateTime, String>();

        while (frequency.Equals("weekly") ? (startDate.AddDays(7) <= endDate) : (startDate.AddMonths(1) <= endDate))
        {
            if (frequency.Equals("weekly"))
            {
                returnDict.Add(startDate, startDate + "-" + startDate.AddDays(7));
                startDate = startDate.AddDays(8);
            }
            if (frequency.Equals("monthly"))
            {
                returnDict.Add(startDate, startDate + "-" + startDate.AddMonths(1));
                startDate = startDate.AddMonths(1).AddDays(1);
            }
        }

        returnDict.Add(startDate, startDate + "-" + endDate);

        return returnDict;
    }

Answer 3

The top solutions will fail if the date includes different hours. Here is a solution getting all hours and all days:

All Days:

static public List<string> get_days_between_two_dates(DateTime start_date, DateTime end_date)
    {
        List<string> days_list = new List<string>();
        DateTime temp_start;
        DateTime temp_end;

        //--Normalize dates by getting rid of minues since they will get in the way when doing the loop
        temp_start = new DateTime(start_date.Year, start_date.Month, start_date.Day);
        temp_end = new DateTime(end_date.Year, end_date.Month, end_date.Day);

        //--Example Should return
        //--1-12-2014 5:59AM - 1-13-2014 6:01AM return 12 and 13
        for (DateTime date = temp_start; date <= temp_end; date = date.AddDays(1))
        {
            days_list.Add(date.ToShortDateString());
        }

        return days_list;
    }

All Hours:

static public List<string> get_hours_between_two_dates(DateTime start_date, DateTime end_date)
    {
        List<string> hours_24_list = new List<string>();
        DateTime temp_start;
        DateTime temp_end;

        //--Normalize dates by getting rid of minutes since they will get in the way when doing the loop
        temp_start = new DateTime(start_date.Year, start_date.Month, start_date.Day, start_date.Hour, 0, 0);
        temp_end = new DateTime(end_date.Year, end_date.Month, end_date.Day, end_date.Hour, 0, 0);

        //--Example Should return
        //--5:59AM - 6:01AM return 5am and 6am
        for (DateTime date = temp_start; date <= temp_end; date = date.AddHours(1))
        {
            hours_24_list.Add(date.ToShortTimeString());
        }

        return hours_24_list;
    }

Answer 4

Here is a quick console app to demonstrate how to do it - use AddDays() instead:

class Program
{
    static void Main(string[] args)
    {

        GetDates(new DateTime(2010, 1, 1), new DateTime(2010, 2, 5));

        Console.ReadKey();
    }

    static List<DateTime> GetDates(DateTime startDate, DateTime endDate)
    {
        List<DateTime> dates = new List<DateTime>();

        while ((startDate = startDate.AddDays(1)) < endDate)
        {
            dates.Add(startDate);
        }

        return dates;
    }
}

Answer 5

static IEnumerable<DateTime> GetAllDatesAndInitializeTickets(DateTime startingDate, DateTime endingDate)
{
    List<DateTime> allDates = new List<DateTime>();


    for (DateTime i = startingDate; i <= endingDate; i = i.AddDays(1))
    {
        allDates.Add(i);
    }
    return allDates.AsReadOnly();
}

Answer 6

How about something like this?

public IEnumerable<DateTime> DateRange(DateTime fromDate, DateTime toDate)
{
    return Enumerable.Range(0, toDate.Subtract(fromDate).Days + 1)
                     .Select(d => fromDate.AddDays(d));
}

Edit: Tested now. :)