AtharvaVeda at least mentions names of Nakshatras as I discuss in my answer here.
Similarly Valmiki Ramayana also gives horoscope of Lord Rama as I discuss in my answer here.
ततो यज्ञे समाप्ते तु ऋतूनाम् षट् समत्ययुः | ततः च द्वादशे मासे चैत्रे नावमिके तिथौ || १८-८ नक्क्षत्रे अदिति दैवत्ये स्व उच्छ संस्थेषु पंचसु | ग्रहेषु कर्कटे लग्ने वाक्पता इंदुना सह || १८-९ प्रोद्यमाने जगन्नाथम् सर्व लोक नमस्कृतम् | कौसल्या अजनयत् रामम् सर्व लक्षण संयुतम् || १८-१० विष्णोः अर्धम् महाभागम् पुत्रम् ऐक्ष्वाकु नंदनम् | लोहिताक्षम् महाबाहुम् रक्त ओष्टम् दुंदुभि स्वनम् ||१८-११
Twice six months had rolled a way since the great sacrifice was over and, in the first month of the New Year, on the ninth day of the bright fortnight, the Lord of the worlds chose to take human form and sent down half of His essence as the son of Kausalya (thenceforth to be known as Rama), the world-honored One, the crowning glory ot the grand line of Ikshwku, and the sum of all perfections. The constellation Punarvasu, of which Aditi was the regent, was chosen to preside at his birth. The Sun, Mars, Jupiter, Venus, and Saturn were in ascension in their respective houses. Aries, Capricornus, Cancer, Pisces and the Libra, Jupiter and the Moon were in conjunction ; the rising sign was Cancer. And KausalyA, shone with unparalleled effulgence, even as Aditi when she gave birth to Indra, the lord of the Shining Ones, the Vajra-wielder.