Why Hindus should celebrate Makara Sakranti on December 21. [Uttarayana]

Hindus made some amazing contribution to astronomy in past but they indeed got many things wrong. One of them was detection of Winter Solstice cycle. Hindus relied on the lunar calendar perhaps because the night sky seemed like an information rich canvas compared to the day sky which only has Sun in it. But lunar movements have nothing to do with solar movements and hence linking solstice day with lunar movement was likely to be mistake.

Hindus celebrate Makara Sankranti in January. People will find it weird to know that the whole point of Sankranti is to celebrate solstice day.

Uttarāyana, “northward course”, is the moment the sun stops its southward course (with ever-shortening days in the northern hemisphere) and turns northwards. It is an exact translation of “the half-year period starting with Winter Solstice”, or simply “Winter Solstice”. However, modern Hindus celebrate this moment on a different date, 14 or 15 January, which they call Makara Sankranti. What has gone wrong? - Asks Dr. Koenraad Elst

The Srimad Bhagavata 5/21/3-6:

 “Placed at the centre of the sky, the glorious sun, the lord of the luminaries, warms by its heat and illuminates by its light the three worlds (heaven, atmosphere, earth).  Coursing by slow, swift and regulated marches known by the names of Uttarayana (the northerly march from the Winter Solstice), Dakshinayana (the southerly march from the Summer Solstice) and the Vaishuvata (Equinox) and rising higher, going down and taking a mean position whenever  and wherever such positions are inevitable, the sun, while passing the Zodiac, from Makara (Capricorn) onwards, lengthens the days while shortening the nights and vice verse and brings their duration on a par."

The Vishnu Purana 2/8/28-31 is even more explicit: “In the beginning of Uttarayana (northward course), the sun enters Makara Rashi (Capricorn), from there going to Kumbha (Aquarius) and then Mina (Pisces). After having passed through these three signs, it just gains Vishuvati (equinoctial) speed resulting in the day and night being equal on Mesha (Aries).(…) Then when the sun is in the end of Mithuna Rashi (Gemini), i.e. when it is just at the verge of entering Karkata (Cancer), the day is the longest then, as Dakshinayana (southward course) starts on that date”.

AK Kaul has been the champion that Hindus should adjust their calendars and start celebrating Makara Sakranti on December 21st instead of linking it to Makara transition. As the years pass we will be celebrating Makara Sakranti in May or June at which point it would appeared nonsensical.

Hindus got the link between zodiacs and sun's movement pretty wrong and that is okay, but we must fix it.