Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s6.t2.3

v2.c12.s6.t2.3

The calculation of the five elements or parts (aṅgas) of the Almanac (Pañcāṅga) is usually given in the Spaṣṭādhikāra (the chapter on true Places); and hence, the question of the almanac is being taken up in this very chapter. Such matters as the Śaka era, the beginning of the year, the samvatsara (year), the “pūrṇimānta” and “amānta” systems etc. are but integral parts of the almanac; after considering these, therefore, the consideration of the five elements of the almanac, the defferent kinds of almanac etc., will be taken up.