The first quarter period of the whole dwadasi is called Harivasaram. It is equivalent to Ekadasi. Consuming rice will result in severe sin. Mostly, dwadasi starts on the same day as the Ekadasi vratam; hence, the first quarter period finishes on that day itself. A few times, the first quarter portion is present on the day following ekadasi vratam day. During such times, only after the Harivasaram period, dwadasi paranai must be done. Because this period is a favored period for Hari, the Perumal, it is named Harivasaram.