avalonia: A couple tweaks and bug fixes for CalendarView

InABox.Avalonia/Components/CalendarView/CalendarView.axaml.cs

@@ -232,7 +232,7 @@ public partial class CalendarView : UserControl
 
         public override string ToString()
         {
-            return $"Block({Column:dd/MM/yyyy}: {StartTime:hh\\:mm} - {EndTime:hh\\:mm})";
+            return $"Block({Column}: {StartTime:hh\\:mm} - {EndTime:hh\\:mm})";
         }
     }
 
@@ -345,7 +345,7 @@ public partial class CalendarView : UserControl
         Canvas.Children.Clear();
         Canvas.Height = rowHeight * nRows;
 
-        var minColWidth = 50;
+        var minColWidth = MinimumColumnWidth;
         var colSpace = 1;
 
         var nColumns = 0;
@@ -626,6 +626,10 @@ public partial class CalendarView : UserControl
                 block.NColumns = nColumns > -1 ? nColumns : columns.Count - i;
             }
         }
+        if(columns.Count == 0)
+        {
+            columns.Add(new());
+        }
         return columns;
     }