Gayatri Japam day is associated with Upakarma day and it is observed on the next day of Shravani Upakarma day.
Young students who learn Veda begin their learning with the Upakarma ritual. On the auspicious day of Shravana Purnima, the sacred thread is adorned with the chanting of Vedic Mantra. The sacred thread is also known as Janeu, Yajnopavita and Jandhyam.
Next day morning, after Upakarma, the person who wears the sacred thread repeatedly chants Gayatri Mantra several times. This repeated chanting of Gayatri Mantra, usually 108 and 1008 times, is called Gayatri Japam. Gayatri Japam is a sacred ritual more popular in South Indian Brahmins.
In Andhra Pradesh and Telangana, the day of Gayatri Japam is known as Gayatri Pratipada or Gayatri Padyami.