The puja
The fast begins at sunrise. In the evening, or in the early morning, women bathe, dress in new clothes and green bangles, and make small images of Shiva, Parvati and Ganesha from sand or clay. These are placed on a platform decorated with a banana-leaf canopy and flowers.
Bathe, wear clean clothes and purify yourself and the place. Make the sankalpa for the puja and worship Ganesha first. Worship Shiva with bilva leaves, datura and white flowers, and Parvati with the sixteen marks of a married woman: a red sari or chunari, sindoor, bangles, bindi, kajal, mehndi, and other ornaments. Offer fruit and sweets, and hear the katha of how Parvati's friends carried her away (harat) to the forest so that she could do penance for Shiva, and how she worshipped a linga of sand on this day.
The vigil and the close
The women stay awake through the night singing songs of Shiva and Parvati, worshipping again in each watch. The next morning the images are worshipped once more and immersed in water, the marks of marriage are given to a married woman or a mother-in-law, and the fast is broken.
Why it is kept
The name Hartalika joins harat, carried off, and alika, a friend: Parvati's friends carried her away so that she would not be married to Vishnu, and she won Shiva by her penance. Women keep the fast for the same steadfast love and a long married life.