Short answer: Ayurveda divides the night into dosha phases. The evening kapha phase (roughly 6-10 PM) is described as heavy and sleep-promoting; after about 10 PM the pitta phase begins, and the texts say alertness rises again. Sleeping within the kapha window is why they urge an early night - anyone who has pushed past sleepiness at 9:30 and found themselves wide awake at 11:30 knows the pattern.
The classical reasoning. The Charaka Samhita counts proper sleep (nidra) as one of the three pillars of health, alongside food and disciplined living. The daily-regimen chapters recommend rising before sunrise and sleeping early enough to make that natural - which works out to lights off around 10-10:30 PM.
A classical wind-down routine that still works
- Dim lights and put screens away after dinner - the texts say the senses should withdraw before sleep.
- A warm, light dinner at least two hours before bed; heavy late dinners disturb both digestion and sleep, in the classical telling.
- Warm milk at bedtime is one of the oldest Indian home sleep habits - plain, or with a pinch of nutmeg as grandmothers did it.
- A few drops of oil massaged into the soles of the feet is the classical last step before sleep.
- Same sleep and wake time every day, including weekends. Routine is the lever the texts return to most.
Where herbs fit
Brahmi, jatamansi and ashwagandha are the classical calming herbs, used at night, as directed by the physician. They support the routine; they do not replace it.
When poor sleep needs a doctor
Loud snoring with pauses in breathing, lying awake most nights for over a month, or daytime sleepiness that affects work or driving.
Sources: Charak Samhita Online Edition (nidra and dinacharya chapters), carakasamhitaonline.com; NIIMH e-Samhita (Ashtanga Hridaya daily-regimen chapters), niimh.nic.in/ebooks. Reviewed by Dr. Renjith N. Raj, BAMS (Reg. No. 17120).