That is odd. There should be a horizontal scroll bar to be able to scroll over to the right. It did need some width-limiting code to prevent it from squishing the sidebar, but this does seem to be very cut-off (although your screen seems quite wide too). Does it let you scroll to the right?
My main screen is a 24 inch wide screen coupled with a 22 inch wide screen. I have tried it on a separate system with a 22 inch screen and the same applies. I can scroll to the right; it’s just inconvenient. As you stated, it is definitely a width-limiting problem. What about responsive scaling like in web pages?.
An extra question; do I assume correctly that the schedule is designed to be a living entity which is updated from year to year as duty cover changes?