Class lenght doesn't display properly

A few problems:

1. The times displayed in the left column do not have the same intervals. eg. I have 9.00, 10.00, 11.00, 12.00 and then 14.00, 15.00, and then 18.00… so 13,00, 16.00 and 17.00 are missing.
I see that this is related to when a class starts, but I would like to have times displayed in 1h intervals.

2. The classes are not displayed in their full length. eg. there is a class on Monday that goes from 9.00 – 10.30, but it looks like it’s until 10.00. Same on Wednesday, a class from 10.00 – 12.00 displays as if it is until 11.00.
How to change this?

Here the link to the page: http://martamarszal.com/test/?page_id=77

http://wordpress.org/plugins/weekly-class-schedule/