Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
अर्यमा भगसंज्ञश्च विज्ञेया दश पंच च ।ईशाजपादाहिर्बुध्न्यपूषाश्वियमवह्नयः ॥ २२५ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 225.
Then Aryama and Bhaga. These fifteen are to be known. Next: Isha, Ajapada, Ahirbudhnya, Pusha, the Ashvins, Yama and Agni.
Simple meaning: The fifteen day muhurtas end with Aryama and Bhaga. A second list of fifteen then begins.
धातृ इन्द्रादितीज्याख्या विष्णवर्कत्वष्टृवायवः ।
Each muhurta is a fifteenth part of the day, and a fifteenth part of the night.
मुहूर्तमानं द्वरावक्षणर्क्षाणि समेश्वरम् ।
A muhurta is one fifteenth of day or night. The bad muhurtas for each weekday begin here.
राक्षसाख्यौ ब्राह्मपित्र्यौ भर्गाजांशाविनादिषु ।
Each weekday has one or two bad muhurtas. Skip them for good acts.