What is tzitzit and when is it worn?

Tzitzit are fringes of thread attached to each of the four corners of a garment, fulfilling Numbers 15:38-40. The daily garment is a tallit katan (small tallit) worn under clothing. Each fringe has 4 doubled threads (8 total) with a specific winding pattern: 7-8-11-13 wraps between double knots. The numerical value of 'tzitzit' (600) + 8 threads + 5 knots = 613, representing all the mitzvot.