Stay 2 days - FOUNDAMENTALS
It's the minimum time to visit Matera. Visiting Sassi means getting lost in the streets and getting caught up by the chaotic complexities of the structures: Via Fiorentini, Via Madonna delle Virtù, St. Peter Caveoso, Grotta, via Bruno Buozzi and then via DAddozio, St. Peter Barisano and Casa Cava. In the afternoon, after the hottest hours, go to the Belvedere of Murgia Timone, to have a breathtaking glance over the city. Try to stay there for the sunset: friends all over the world still thank me for this suggestion!
Have dinner in one of the many typical restaurants to taste the Matera bread, PDO and a pride of the town.
The next day, visit Civita and the "piano": House Noha, to better understand the history of Matera through a movie made by the FAI over the city, the Cathedral, recently restored, Palazzo Lanfranchi with the famous painting by Levi Lucania ' 61, the delicious piazza Ridola and stop there for an appetizer. Then the Palombaro Lungo, figuring the water collection system which earned the UNESCO recognition of world heritage.
Unfortunately you already have to go away, but if you still have some time, you can visit the monastery of the Madonna delle Virtù and San Nicola dei Greci, to get an idea of the rock churches.