On Shravana Purnima, sisters tie the rakhi, a thread of protection, on their brothers' wrists; the muhurat avoids the Bhadra period.
Raksha Bandhan, the bond (bandhan) of protection (raksha), falls on Shravana Purnima. A sister ties a rakhi on her brother's wrist and prays for his long life; he pledges her protection. Legends trace it from Draupadi and Krishna to Rani Karnavati's rakhi to Humayun.
The rakhi should be tied while Purnima prevails but never during Bhadra. Classically the Aparahna (afternoon) window is best. The daily panchang on this site shows the Bhadra window for your city.
Shravana Purnima is also Narali Purnima on the Konkan coast (coconut offerings to the sea) and Avani Avittam / Upakarma, when the sacred thread is renewed in South India.