The code is the same as before, with the following changes:
In planner.ascx Add a method call to DataBind in the Page_Load event, inside the postback check, and also to the end of the SelectionChanged method, after the if statement.
Remove the lines DayLabel.Text = (Calendar1.SelectedDate).Format("dddd, MMMM dd yyyy", nothing ) and DayLabel.Text = (obj.SelectedDate).Format("dddd, MMMM dd yyyy", nothing ) from the Page_Load and SelectionChanged events, respectively.
Add the line Text='<%# Calendar1.SelectedDate.Format("dddd, MMMM dd yyyy", nothing ) %>' to the declaration of DayLabel.
Be sure to import the System.Data namespace!