Not familiar with Swedish Fish specifically, but generally candy is mostly sugar, which is a preservative in itself so it doesn’t really go off. Also not familiar with the regulations in your area, but in my country foods are generally good for at least three months outside of a “best before” date if kept in their original packaging or at least airtight. Flavour and texture might decline a bit, but they won’t make you sick. It’s the “use by” dates you want to be observant of.