A lunar month, about October to November
Sanskrit name of a lunar month, from the nakshatra (star) near its full moon: Krittika.
Kartika falls in about October to November on the solar calendar, and is the month of Diwali, Chhath Puja and Tulsi Vivah, kept as holy for lamps and for bathing at dawn. The exact dates move a little each year because the Hindu calendar follows the moon.
Diwali is a five-day season at the Kartika new moon (October-November). This sets out the days, the Padma Purana and al-Biruni, and which stories are later.
Tulsi Vivah is the wedding of Tulsi to Vishnu on Kartika Dvadashi. The article sets out the day, what the Puranic chapters say, and why the wedding is described as custom.
The divine katha of Harishayani Ekadashi marking the beginning of the four sacred months of Chaturmas when Lord Vishnu rests upon Sheshanaga.
The glorious story from the Brahmavaivarta Purana of Princess Chandrabhaga and Prince Shobhana attaining the heavenly Gandharva city of Devapuri on Rama Ekadashi in Kartika Krishna Paksha.
Chhath in order: Nahay Khay, Kharna, then standing in water to offer arghya to the setting and rising Sun, with the fast, the offerings and Chhathi Maiya.
The Karva Chauth fast and worship in order, from sargi to the moon and the first sip, with the mantras printed by almanac pages and what no early text says.