Complex sentence: July 16, marks the transition of the Sun into Karka rashi (Cancer), thus signifying the end of the six-month Uttarayana period of Hindu calendar, and the beginning of Dakshinayana, which itself end at Makar Sankranti.
Split into simpler sentences: July 16, marks the transition of the Sun into Karka rashi (Cancer). This also marks the end of the six-month Uttarayana period of Hindu calendar, and the beginning of Dakshinayana, which itself end at Makar Sankranti.