Question

public static string TimeLine2(this HtmlHelper helper, string myString2)
{
    StringBuilder myString3 = new StringBuilder();

    DateTime start = new DateTime(2010, 1, 1);
    DateTime end = new DateTime(2011, 12, 12);

    myString3.Append("<table>");


        myString3.Append("<tr>");
        for (DateTime date = start; date <= end; date = date.AddDays(1))
        {
            DayOfWeek dw = date.DayOfWeek;
            var g = date.Month;
            var sun = " ";

            switch (dw)
            {
                case DayOfWeek.Sunday:
                    sun = "S";
                    break;
                case DayOfWeek.Monday:
                    sun = "M";
                    break;
                case DayOfWeek.Tuesday:
                    sun = "T";
                    break;
                case DayOfWeek.Wednesday:
                    sun = "W";
                    break;
                case DayOfWeek.Thursday:
                    sun = "T";
                    break;
                case DayOfWeek.Friday:
                    sun = "F";
                    break;
                case DayOfWeek.Saturday:
                    sun = "S";
                    break;
            }

            myString3.Append("<td>" + sun + " " + g + "</td>");
        }

        myString3.Append("</tr>");

        myString3.Append("<tr>");
        for (DateTime date = start; date <= end; date = date.AddDays(1))
        {
            var f = date.Day;
            myString3.Append("<td>" + f + "</td>");
        }
        myString3.Append("</tr>");

    myString3.Append("</table>");

    return myString3.ToString();
}

Basically, what I have here is a few loops showing all the days of the week and also all the days in a month. This is all placed inside of a table, so you get

MTWTFSSMT W T F S S  M          M  TWTFSSM

    12345678910 11 12 13 14  + + to 31 1234567

I’m trying to code a way in which I can split all of these days of the week and days in months so that my code returns each month with all its days in the month and all its days of the week, not just all my months between my timeSpan but splits them so

MAY
MTWTFSSMTWTFSSMTWTFSSMTWTFSSMTWTF
    12345678

JUNE
MTWTFSSMTWTFSSMTWTFSSMTWTFSSMTWTF
    123456789

Answer 1

Using LINQ:

DateTime startDate = new DateTime(2010, 1, 1);
DateTime endDate = new DateTime(2010, 12, 31);

int monthCount =
    (endDate.Month - startDate.Month + 1) +
    (endDate.Year - startDate.Year) * 12;

Enumerable
    .Range(0, monthCount)
    .Select(x => new DateTime(startDate.Year, startDate.Month, 1).AddMonths(x))
    .ToList()
    .ForEach(d1 =>
    {
        string month = d1.ToString("MMMM");
        // here should be your code
        // to work with months

        Enumerable
            .Range(0, d1.AddMonths(1).AddDays(-1).Day)
            .Select(x => d1.AddDays(x))
            .ToList()
            .ForEach(d2 =>
            {
                string dayOfWeek = d2.ToString("ddd");
                string day = d2.Day.ToString();
                // here should be your code
                // to work with days
            });
    });

OK, the next variant without LINQ:

StringBuilder sb = new StringBuilder();

DateTime startDate = new DateTime(2010, 1, 1);
DateTime endDate = new DateTime(2012, 12, 31);

int monthCount =
    (endDate.Month - startDate.Month + 1) +
    (endDate.Year - startDate.Year) * 12;

for (int i = 0; i < monthCount; i++)
{
    DateTime d1 = new DateTime(startDate.Year, startDate.Month, 1).AddMonths(i);
    string month = d1.ToString("MMMM");

    sb.AppendFormat("<p>{0}</p>", month);

    int daysInMonth = d1.AddMonths(1).AddDays(-1).Day;
    StringBuilder daysOfWeekRow = new StringBuilder();
    StringBuilder daysRow = new StringBuilder();
    for (int j = 0; j < daysInMonth; j++)
    {
        DateTime d2 = d1.AddDays(j);
        string dayOfWeek = d2.ToString("ddd");
        string day = d2.Day.ToString();

        daysOfWeekRow.AppendFormat("<td>{0}</td>", dayOfWeek);
        daysRow.AppendFormat("<td>{0}</td>", day);
    }
    sb.AppendFormat(
        "<table><tr>{0}</tr><tr>{1}</tr></table>",
        daysOfWeekRow.ToString(), 
        daysRow.ToString()
    );
}

string result = sb.ToString();

You may change output formatting as you want I provided the basic example only.

The main thing is to iterate through the necessary dates (to use or not to use LINQ is you option, but you could agree solution with LINQ is more elegant) and add custom formatting in the necessary places (I put comments where to do it with the first example).