Surya Siddhanta
शीघ्रगस् तान्य् अथाल्पेन कालेन महताल्पगः। तेषाम् तु परिवर्तेन पौष्णान्ते भगणः स्मृतः ॥
The planet which moves rapidly, requires a short time, to pass the signs (of the Zodiac,) and the planet that moves slowly, passes the signs (of the Zodiac) in a long time. Bhagaṇa means that revolution through the signs (of the Zodiac which a planet makes by passing round) up to the end of the true place of the star called Reváti (ζ Piscium, from which end they set out.)
english translation
zIghragas tAny athAlpena kAlena mahatAlpagaH। teSAm tu parivartena pauSNAnte bhagaNaH smRtaH ॥
hk transliteration by Sanscript