Sage Agastyar says
यो देवः सवितास्माकं धियो धर्मादिजोचराः ।
प्रेरयेत् तस्य यद्भर्गः तत्वरेण्यम् उपास्महे ॥
yo devaH savitAsmAkaM dhiyo dharmAdijocharAH |
prerayet tasya yadbhargaH tatvareNyam upAsmahe ||
We meditate on the glory and Effulgence of Surya (Savitah), to let Him guide us by kindling our intellect.
Pongal – the start of the Tamil month of Thai – marks the beginning of a new celestial day for the Gods, while Margazhi is regarded as pre-dawn (or Brahma muhurtam). It also marks the important occasion of Uttarayanam – when the Sun begins its journey from the southern part of the skies, to the northern.
Many temples have separate entrances to the garbhagriham, depending on the time of the year as uttarayanam or dakshinayanam.
More importantly, it is the start of the “day” of the celestials, whose one day is one year on bhulokam. It is also the day when Suryan enters the Makara Rasi; in Sanskrit, Sankramanam refers to transition or movement, and therefore Makara Sankranti is the day of transition of Suryan to the Makara Rasi.

In society today, the Pongal festival is celebrated by offering worship to Suryan. Particularly in Tamil Nadu and the southern part of India, there is also a thematic menu that is prepared on the occasion of Pongal. Why this menu is as interesting as it is specific? Take a look here.

Next, is the Panangateeswarar temple at Panaiyapuram near Viluppuram, which has a puranam very closely associated with Suryan and the Daksha Yagam.

Finally, we take a look at some temples with interesting connections to the Pongal festival and celebrations, and pongal as a food item.