When an event has a start date and a later end date, Organise You can treat it in two different ways.
One event spanning several days
Use this for things such as holidays, annual leave, trips or conferences. It appears as a continuous multi-day bar and has one overall status.
The same event happens each day
Use this when you actually do the same thing separately on each day, such as taking someone to a class on Tuesday, Wednesday and Thursday. Organise You creates a daily series ending on the final date, so each day can be marked completed separately.