Since ancient times, the Hindus have had a lunisolar cycle based on the combination of solar and lunar years, determined by the course of the sun and the moon, but with the lunar year beginning near the solar year. Exactly how their earliest Calendar was arranged remains a mystery. Our focus is on the current form of their Calendar, developed around 400 under the influence of Greek astronomy and introduced into India at no long time.
There are two kinds of Hindu years, solar and lunar.
To understand the lunar Calendar, we will first explain the solar year, which governs the lunisolar system. Bengal, including Madras's Orissa, Tamil, and Malayalam districts, used solar years for civil purposes. General religious rites and festivals are regulated by the lunar year and the details of private and domestic life, such as choosing auspicious occasions for marriages and journeys, choosing lucky moments for shaving, etc. Almanacs that follow the lunar year contain details about the solar year, such as the sun's course through the zodiac signs. Despite following the solar year, almanacs include lunar year details.