Sukk'ot (The Feast of Tabernacles), beginning on Tishri 15, is the third of God's three ordained Annual High Sabbaths — the "Pilgrimage" Sabbaths. It is a 7-day feast during which God commanded Israel to dwell in temporary booths (sukkahs) to commemorate the wilderness wandering.
Christ Jesus was born on the first day of Sukk'ot — Tishri 15, the year 3758 on the Hebrew calendar (October 4, BCE 4). He was literally born in a sukkah (tabernacle / booth) and placed in a manger (food crib) — demonstrating in a "Type" that He is the Bread of Life from heaven.
The Feast of Tabernacles is one of the three God-ordained High Holy Days (Annual High Sabbaths). The other two are Nisan 15 (first day of Unleavened Bread) and Shavu'ot (Pentecost, 50 days from the Sunday following Passover).
For the full account of Christ Jesus' birth at Sukk'ot, see FAQ 02 — When Was Christ Jesus Born?