You can create your own custom format provider to do this:
public class MyCustomDateProvider: IFormatProvider, ICustomFormatter
{
public object GetFormat(Type formatType)
{
if (formatType == typeof(ICustomFormatter))
return this;
return null;
}
public string Format(string format, object arg, IFormatProvider formatProvider)
{
if (!(arg is DateTime)) throw new NotSupportedException();
var dt = (DateTime) arg;
string suffix;
if (new[] {11, 12, 13}.Contains(dt.Day))
{
suffix = "th";
}
else if (dt.Day % 10 == 1)
{
suffix = "st";
}
else if (dt.Day % 10 == 2)
{
suffix = "nd";
}
else if (dt.Day % 10 == 3)
{
suffix = "rd";
}
else
{
suffix = "th";
}
return string.Format("{0:MMMM} {1}{2}, {0:yyyy}", arg, dt.Day, suffix);
}
}
This can then be called like this:
var formattedDate = string.Format(new MyCustomDateProvider(), "{0}", date);
Resulting in (for example):
March 3rd, 2012