Why Terai Holi is the day after Falgun Poornima?

Today, players of different colors of the country, including Kathmandu, are relaxing. In fact, those who enjoyed the colors in the hills, inner Madhes and central hills of Nepal, exchanged colors and ecstasy yesterday. Now it is the Holi for flatlands and scattered trees of Terai. Traditionally, Terai region celebrates this festival a day later.