संक्रान्तिः
Sankranti — The Sun's Solar Transits
सम् (sam, "together, fully") + क्रान्ति (krānti, "stepping, moving") — Sankranti marks the Sun's transit from one zodiac sign into the next. Unlike Tithi-based festivals, all 12 Sankrantis are solar events and fall on nearly the same Gregorian date every year.
Dates are standard solar-transit approximations, accurate to within a day.
Makar Sankranti — the best-known one
Of the 12, Makar Sankranti (the Sun's entry into Capricorn, mid-January) is by far the most widely observed, marking the start of Uttarayana — the Sun's six-month northward journey, traditionally considered an auspicious half of the year.
See our Solar Calendar guide for how Sankranti fits into India's broader solar calendar traditions.