I stay in Seattle, USA and this is my way of staying connected to my roots and in fact I enjoy, celebrating these festivals. It brings memories untold from your motherland.:) I am making a record of these, for people who wish to celebrate and stay connected with their roots. Upakarma means beginning and it refers to the ritualistic beginning of learning Veda. Apart from learning Vedas on Upakarma day, men also change their yagnopaveetham / sacred thread. Upakarma is still practiced by Hindus of Brahmin community.
Those who follow Yajurveda observe the Upakarma on the full moon day during Shravana month on Shravana Poornima day which was yesterday on August 17th. Men change their sacred thread during upakarma and chant Gayatri Mantra before and after changing the sacred thread.
The main purpose of Upakarma is to offer prayers and express the gratitude to those Rishis who gave the knowledge of Vedas and revealed Vedic Mantras to the mankind. The next day of Upakarma is known as Gayatri Japam Day which is today August 18th.
Gayatri Mantra for reference:
Om bhūr bhuvaḥ svaḥ
tát savitúr váreṇ(i)yaṃ
bhárgo devásya dhīmahi
dhíyo yó naḥ prachodayāt