Paro and Thimphu Festivals are by far the most popular festivals in Bhutan. There are two main reasons why they are so popular. Firstly, they are located in the Western part of Bhutan, an hour drive away from the airport. So it is possible for you to do a four days visit just to attend the festival. If the festival is taking place in Eastern Bhutan, you would have to visit Bhutan for a minimum of 10 days. Secondly, Paro and Thimphu Festivals take place in spring and autumn respectively, 2 of the best seasons to visit Bhutan.
Three years ago, we would usually recommend travelers to books at least six months before their travel dates. With the growing number of hotels in Bhutan, we can usually accommodate travelers on last minute notice. However, do note that experienced guides are in high demand during this period. If you do have some flexibility with your travel schedule, we would recommend going for less popular festivals.