The ideal duration for a visit to Skopje, really depends on your interests and what you want to experience. If you’re interested in seeing the main attractions in the city center, such as the Old Bazaar, Stone Bridge, Kale Fortress, and Macedonia Square, you could probably visit all them in a day or two.
However, if you want to delve deeper into the city’s culture, history, and cuisine, I’d recommend spending at least three to four days in Skopje. This would give you enough time to explore the various museums, take day trips to nearby attractions like Matka Canyon or the Millennium Cross, and sample the local food scene.
Ultimately, the duration of your stay in Skopje should align with your interests and how much time and money you have available for your trip.