A lunar fortnight has hither to consisted of fourteen days, or fifteen days or sixteen days. But on the thirteenth day and in the course of the same month two eclipses have taken place.
चतुर्दशी पञ्चदशी भूतपूर्वां च षोडशीम्। इमां तु नाभिजानेऽहममावास्यां त्रयोदशीम्। चन्द्रसूर्यावुभौ ग्रस्तावेकमासी त्रयोदशीम्॥