This fortnight is the most consequential turn in the classical calendar, and almost nobody notices it.
The year divides into two halves. Adana kala, roughly January to July, is the taking half: the sun's course progressively dries the earth and depletes the body, and strength declines steadily from a January high to a monsoon low. Visarga kala, roughly July to January, is the giving half: moisture returns, the moon's influence dominates in the tradition's account, and strength is restored. Hemanta sits in the strong part of the giving half, and the texts state it plainly — bala is at its maximum in Hemanta and Shishira, and at its minimum in Grishma and Varsha.
What that means physically: cold outside contracts the body's surface and drives heat inward, and agni — no longer dissipated at the periphery — burns hotter than at any other point in the year. Appetite becomes large and genuine. If it is not fed adequately, agni turns on the body's own tissues, which is the classical explanation for winter fatigue, joint dryness and Vata aggravation in people who diet through the cold.
So Hemanta reverses the year's instructions, and this is the fortnight to make the switch. Eat more, not less. Heavier, sweeter, more unctuous, more substantial. Sweet, sour and salty tastes lead now — the three that were restrained through Pitta season. Meat, if you eat it; ghee, oils, milk, whole grains, root vegetables, nuts, dates and jaggery if you don't. This is the one season where the tradition actively recommends abundance.
And the sandhi rule for the last time this year: a week to let autumn's cooling go, a week to bring in winter's warmth. Do not go from bitter greens to ghee-laden food overnight.
Strength training, abhyanga, rasayana, and the year's genuinely good sleep all belong to the next eight weeks. There is no better window and there will not be another one for twelve months.