Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
सविष्णुभेषु क्रमशो हस्तभाच्चंद्रसंयुतः ।धिष्ण्ये तावति सत्यत्र दुष्टयोगः पतत्यसौ ॥ २३४ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 234.
... and to Shravana, each in turn. Count as many stars on from Hasta. If the Moon is in that star, this bad combination falls.
Simple meaning: Count from the Sun's star to certain stars. The same count from Hasta gives a bad Moon star.
चंडीशचंडायुधाख्यस्तस्मिन्नैवाचरेच्छुभम् ।
This bad combination is called Chandisha-Chandayudha. Do no good act in it.
क्रकचो नाम योगोऽयं मंगलेष्वतिगर्हितः ।
Tithi plus weekday making 13 is Krakacha, very bad. Sunday on the 7th or Wednesday on the 1st opens another.
संवतयोगो विज्ञेयः शुभकर्मविनाशकृत् ।
Those two pairs make Samvata, which can spoil good acts. The list of 28 day mixes begins with Ananda.