Chaitra month is 1st lunar month in Hindu calendar. As per the Gregorian calendar, Chaitra month falls between March-April.
As per Hindu calendar each month based on moon that is known as lunar month. According to this Purnima to Purnima which is known as the Purnimanta calendar. And another is from Amavasya to Amavasya which is known as the Amanta calendar.
Some important festivals of hindi Chaitra month are Sheetala Ashtami, Papmochani Ekadashi, Gudi Padwa, Gangaur, Yamuna Chhath, Ram Navami, Hanuman Jayanti.