hi,
hab hier mal schnell was zusammengetippt gibt vielleicht noch ne besser Lösung, aber vielleicht hilft es dir ja.
string [] sMonth = {"Januar","Februar","März","April","Mai","Juni","Juli","August","September","Oktober","November","Dezember"};
DateTime startDate = new DateTime(2000,1,1);
DateTime endDate = DateTime.Now;
DateTime tmpDate = startDate;
int iMonths = ((endDate.Year - startDate.Year) * sMonth.Length);
iMonths += endDate.Month;
comboBox1.Items.Clear();
for(int i=0;i<iMonths;i++)
{
tmpDate = startDate.AddMonths(i);
comboBox1.Items.Add(sMonth[tmpDate.Month-1]+" "+tmpDate.Year);
}