Here is your short paragraph on Haritalika:
The third day of the waxing fortnight of Bhadrapada (August/September) is called Haritalika Tija.
On this auspicious day, the luminous goddess ‘Mangala Gauri’ is especially worshipped, as are some of the other great devis of Kashi.
Women keep this day as a fast in order that their husbands might live long or if they are single, in order to get good husbands. They tell the story of Parvati’s persistence in winning the great Shiva as a husband.
Haritalika/Tija is thus related to Siva and Parvati. As said, this is observed to get long life of the husband, his prosperity, health and well-being of whole family. In most of the houses married women keep full day fast with fried cookies in the night.