first of all thanks for your reply.
The issue happened to one of our costumers in New Zealand.
I asked our costumer to provide us with the information you asked. as far as i know
1. It is reproducible on different browser (Chrome & Safari)
2. It is reproducible on different machines (both Mac windows always works fine).
3. I created a test application for our costumer in order to contradict any changes or effects the scheduler (since we customized it and restyle it to our purpose. I just sent him single page app with scheduleview control on it with no extra definitions just the default week definition. on the side i added a combobox which contains some different culture code and when the user selects one i change the culture and recreate the scheduler with the new setting. Attached you can find the results. pay attention that the bug only occurs when the culture and uiculture are co-nz (New Zealand).
you can try the test app on :
If i have further info i'll share it with you.