Return day Name in c#

Rather try something like

MessageBox.Show(DateTime.Today.DayOfWeek.ToString());

DateTime.Today Property

Gets the current date.

Your problem is that

DateTime date = new DateTime(DateTime.Now.Date.Day);

evaluates to

{01/Jan/0001 12:00:00 AM}

The constructor you used was DateTime Constructor (Int64)

Initializes a new instance of the DateTime structure to a specified
number of ticks.