Sat, Sun: 10 AM to 4 PM
Copenhagen is delightfully cycle-friendly, with bike lanes on most major streets. They have a free bike program where you can grab a bike from a rack, ride it across town, and leave it at a different specially designated rack. You’ll need a 20 kroner coin, which serves as a deposit. Stick the coin in the slot on the handle bars to release the key. The coin stays in the slot as you ride. When you return your bike at another rack, insert a key in the coin slot and out pops your 20 kroner. Racks are all over the city.
You can always spot the free bikes because they have solid wheels instead of traditional bicycle spokes. They get a lot of use, so many are in somewhat clunky condition, but for a quick spin through town, they do the trick.
For a more serious day of biking, consider renting a bike in better condition from Cykelsenter, located inside the main train station or a bike rental company near the train station.