If you check the Notes Designer Help on creating Calendar Views, you will find a good amount of documentation that is quite helpful.
Quickly put, a Calendar view needs to be defined as a Calendar view on creation, needs the first column to be a Date/Time column, and needs the values for that column to include date AND time information (not just date information).
Make a search for Calendar Views in the Designer Help, and find the Creating option. It has a step-by-step procedure that cannot fail.
Pascal.