अनध्यायः

कालादर्शे—
पूर्वश्चोर्ध्वमनध्यायमहः सङ्क्रमणे निशि।
दिवा पूर्वोत्तरा रात्रिरिति वेदविदो विदुः॥

Anadhyayana during the day, since saGkramaNa happened during night time yesterday. When saGkramaNa happens in the night, the previous and next day (daylight time) are anadhyayana. If saGkramaNa happens in the night, the previous and next nights are anadhyayana.