In Punjab though the solar calendar is generally followed, the lunar calendar used is purṇimānta, or calculated from the ending moment of the full moon: the beginning of the dark fortnight.Krishnamurthi Ramasubramanian, M. S. Sriram (2011) Tantrasaṅgraha of Nīlakaṇṭha Somayājī. Springer Science & Business Media S. Balachandra Rao (2000) Indian Astronomy: An Introduction. Universities Press Chait is considered to be the first month of the lunar year.Salvadori, Cynthia (1989) Through open doors: a view of Asian cultures in Kenya. Kenway Publications The lunar year begins on Chet Sudi: the first day after the new moon in Chet.Singh, Gursharan (1996) Page 262 Punjab history conference. Punjabi University This means that the first half of the purṇimānta month of Chaitra goes to the previous year, while the second half belongs to the new Lunar year.
