Both. There is a cherry-pick of hours, usually they go by season, and you will pick the shifts you're able to work for according to the season, prompted by seniority of staff. This will be your fixed hours, unless otherwise stated. But, if you need a day off or can't come in the next couple of shifts then, if you're unionized, it's fine -- I can't speak for non-unionized stores.
Id say that Swiss chalet can work around your schedule as best as they can.
Manager never checked dates requested off, always posted on last day of the week. Never 2 weeks in advanced, and never correct. We had to make a facebook group where all front of house staff could communicate and fix the managers mistakes.
Flexible working hours
Hours are set and are not distributed evenly.