Shiva Purana
अहः पक्षं तथा मासमृतुं चायनवत्सरौ॥ स्थूलसूक्ष्मगतैश्चिह्नैर्बहिरंतर्गतैस्तथा ॥ ७ ॥
The day, the fortnight, the month, the season, the transit of the sun and the year can be known by means of the subtle or gross, external or internal signs.
english translation
ahaH pakSaM tathA mAsamRtuM cAyanavatsarau॥ sthUlasUkSmagataizcihnairbahiraMtargataistathA ॥ 7 ॥
hk transliteration by Sanscript