Figuring out weeks in a month

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
 
namespace Testing
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            int Year = 2007;
            int Month = 12;
 
            //Create a Totals array one Int node for each full week
            ArrayList Totals = new ArrayList(FullWeeksInMonth(Year, Month));
            for (int i = 0; i < FullWeeksInMonth(Year, Month); i++)
            {
                Totals.Add(new int());
            }
 
            //Itterate over each days of the full weeks
            for (int i = FirstMonday(Year, Month); i <= LastSunday(Year, Month); i++)
            {
                DateTime CurrentDay = new DateTime(Year, Month, i);
                int CurrentWeekNumber = WeekNumber(CurrentDay);
                int CurrentWeekTotal = (int)Totals[CurrentWeekNumber-1];
                CurrentWeekTotal += GetTotalForDay(CurrentDay);
                Totals[CurrentWeekNumber - 1] = CurrentWeekTotal;
 
            }
 
            //now we write out the data of our Totals List
 
            for (int i = 0; i < Totals.Count; i++)
            {
                Response.Write(string.Format("Week {0} Total: {1}<br/>", i + 1, Totals[i]));
            }
        }
 
        private int GetTotalForDay(DateTime CurrentDay)
        {
            int outValue = 0;
            //Get Total for CurrentDay
            return outValue;
        }
 
        private int FirstMonday(int Year, int Month)
        {
            DateTime FirstMonday = new DateTime(Year, Month, 1);
            while (!(FirstMonday.DayOfWeek == DayOfWeek.Monday))
            {
                FirstMonday = FirstMonday.AddDays(1);
            }
            return FirstMonday.Day;
        }
 
        private int LastSunday(int Year, int Month)
        {
            int LastDay = DateTime.DaysInMonth(Year, Month);
 
            DateTime LastSunday = new DateTime(Year, Month, LastDay);
            while (!(LastSunday.DayOfWeek == DayOfWeek.Sunday))
            {
                LastSunday = LastSunday.AddDays(-1);
            }
            return LastSunday.Day;
        }
 
        private int WeekNumber(DateTime theDate)
        {
            int DaysAfterFirstMonday = theDate.Day - FirstMonday(theDate.Year,theDate.Month);
 
            return (DaysAfterFirstMonday / 7)+1;
        }
 
        private int FullWeeksInMonth(int Year, int Month)
        {
            return ((LastSunday(Year, Month) - FirstMonday(Year, Month)) / 7) + 1;
        }
    }
}
                                              

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
61:
62:
63:
64:
65:
66:
67:
68:
69:
70:
71:
72:
73:
74:
75:
76:
77:
78:
79:
80:
81:
82:
83:
84:
85:
86:
87:
88: