# The house was completed

"They completed God's house" or "They finished building the temple" 

# the third day of the month of Adar

The name of the twelfth and last month of the Hebrew calendar. It is during the cold season. The third day is near the middle of February on Western calendars. 

# sixth year

King Darius had been ruling for five years, so he was now in year number six of his reign.