श्रीमद्वाल्मीकिरामायणे अरण्यकाण्डे षोडशस्सर्गः (४२व श्लोकमु)
Valmiki maharshi describes the lifestyle of SitaRamaLakshmanas during chilling winter season in the forest. Even in that biting cold, they woke up by the start of Brahma-muhurtam (i.e., by ~4:24am; assuming sunrise at 6am), reached the banks of Godavari, took bath in its ice-cold waters, and were ready for daily anushthaanam by the start of the Pratah-Sandhya-Samayam (i.e., by ~5:12am).
The above shloka says, “They then offered Tarpanams to PitruDevatas, and Devatas. They performed dhyaanam of Surya-Bhagavaan and other Devatas”.
This gem of a shloka illustrates the impeccable aachaaram of Sita-Raama-Lakshmanas. Even in terrible winter, in the forest, their morning schedule was un-affected. After bath in holy waters, they offered salutations to Gods as per the Shaastras. Valmiki maharshi describes the severity of cold by saying “even extremely thirsty elephants are afraid of chilling waters and are not putting their trunks into the water”.