“Chanukat ha-Mizbeach” – the dedication festivities, celebrating the completion of the First Beit ha-Mikdash in Jerusalem built by King Solomon, began on the 8th of Tishrei, 2935 from creation. Including the days of Succoth, the celebrations in Jerusalem that year lasted for 14 days.
Then Solomon assembled the elders of Israel, and all the heads of the tribes, the princes of the fathers’ (houses) of the children of Israel, unto king Solomon in Jerusalem; to bring up the ark of the covenant of the Lord out of the city of David, which is Zion. And all the men of Israel assembled themselves unto king Solomon at the feast in the month Ethanim, which (is) the seventh month. (Melachim I, Chapter 8, 1-2)
The month of Ethanim is known today as the month of Tishrey. This name comes from the Hebrew word “Eitan” which means “mighty”. Some say this name is given because there are more special days in this month than in any other month of the year. Among them are Rosh ha-Shanah, the Days of Awe and Yom Kippur. During these days the judgement is passed on the world for the coming year. Another reason why this month is considered “mighty” is because it offers the greatest opportunity for a person to improve himself. (Yalkut “Meam Loez”)
The celebration began seven days before the holiday of Succoth and lasted until the holiday began. The holiday itself was another seven days.
The First Beit ha-Mikdash served as the epicenter of Jewish life for 410 years.
It is said that the dedication of the Third Beit ha-Mikdash in the days of Mashiach will also last seven days:
For seven days shall they effect atonement for the altar, and purify it and dedicate it… (Ezekiel, Chapter 43, 26)
Source: The Book of Melakhim 1, 8; Yalkut “Meam Loez” (on Melakhim 1, 8).