Is there a way (hopefully easy without overriding drawing methods) to set the width of appointments in DayView. Right now the cover about 90% of the width of the column. When trying to create another appointment for the same time the user (even I) have a hard time positioning the mouse to select the time slot without clicking on the appointment.
No, that cannot be changed. SInce multiple appointments can intersect with the same TimeSlot(s), the width of each one is reduced to provide room for the others. When an appointment is the only one in a given range of time slots, it is given all the available space in the interest of making as much of the text visible as possible.
You can theoretically modify the widths using the IUIElementCreationFilter interface, but we strongly recommend not doing so because the logic that calculates the widths is complicated and you would be interfering with it if you changed the width of the elements.
Our software needed to do the same thing. We ended up having to modify the source code of the control, which is certainly not something we hoped to do. I would welcome a programmatic way to reserve some part/percentage of the width.