Is it already time to change tires?

I already see and hear a lot of cars with spike and normal snow tires. It is not cold yet and I thought you were only allowed to use them from a certain date. I have to check on the internet when it is allowed to have your car equipped with winter tires. Each year there is a traffic jam for let your tires get changed at some car garages. We always do it ourselves. We have two complete sets of wheels; one for the summer and one set for the winter. One of our cars does not have spike tires. At some place in the city of Stockholm those tires are forbidden. Those tires damage the pavement of the street and they produces a lot of dust.