उदितेऽनुदिते चैव समयाध्युषिते तथा । सर्वथा वर्तते यज्ञ इतीयं वैदिकी श्रुतिः ॥ १५ ॥
(Thus) the (Agnihotra) sacrifice may be (optionally) performed, at any time after the sun has risen, before he has risen, or when neither sun nor stars are visible; that (is declared) by Vedic texts.