If you only want to explore the historic core, then one day in Split will be enough for you. However, if you have more time at your disposal the 3, 5 and 7-day itineraries are perfect for you. You'll notice that the longer the itinerary, the more of the surroundings you'll be able to explore.

For most travelers, three days is the "sweet spot" for Split, Croatia. One full day is needed to explore the historic center, specifically Diocletian's Palace (a UNESCO site where people still live and work), the Riva promenade, and the Marjan Hill viewpoints. A second day is ideal for the local beaches (like Bačvice) or a quick trip to the nearby medieval town of Trogir (30 mins away). The third day is best used for a full-day excursion, such as a boat trip to the Blue Cave and Hvar Island or a visit to Krka National Park to see the waterfalls. If you intend to use Split as a "home base" to explore more of central Dalmatia or go island-hopping, five to seven days would be appropriate. However, if you are simply passing through on a coastal road trip, one very long day is enough to see the palace and have a nice dinner, though you will miss the relaxed "pomalo" (slowly) vibe that the city is famous for.