Haggai only contains two chapters and 38 verses total. This makes it the second smallest Biblical book in terms of chapters and the fifth smallest in terms of verses.
Date Written, Location
Chronologically, Haggai is the third youngest book both of the Minor Prophets and of the Old Testament in general. His work, written in 520 A.D., is only older than Zechariah (520 to 518) and Malachi (c. 400 A.D.). The book itself was written in the territory formerly known as the Kingdom of Judah.
[Where Were Bible Books Written?]
The Author
Haggai's name means "feast" or "solemnity" (Strong's Concordance #H2292). He was one of the many Jewish captives who returned to Judah after being exiled in Babylon.
[Map of Babylonian Empire at its Peak]
There is no Biblical information about Haggai's family, where he lived, how he made a living and so on. The Bible is also silent regarding how the prophet died, how old he was at death and where he was buried.
A possible hint does exist regarding the prophet's age when he penned his book in 520. God, in chapter two, may be alluding to Haggai being old enough to remember when Solomon's temple existed prior to its destruction in 586 B.C.
Who is left among you that saw this house in her first glory? and how do ye see it now? is it not in your eyes in comparison of it as nothing? (Haggai 2:3).

Time Period
Haggai opens by revealing the exact time the Lord gave him a message to convey to both governor Zerubbabel and the High Priest Josedech.
[What Are the High Priest's Duties?]
In the second year of Darius the king, in the sixth month, in the first day of the month, came the word of the Lord by Haggai the prophet . . . (Haggai 1:1).
The Lord spoke to Haggai on the first day of the sixth Hebrew month, or Elul 1, in 520 B.C. This corresponds to Sunday August 27. The book closes with two messages the prophet received on Kislev 24 of the same year (Haggai 2:10, 20) which corresponds to Sunday, December 17. This makes the book cover a span of 113 days inclusive.
[What is the Biblical Calendar?]
Haggai Chapter Outline
Chpt. 1: The prophet Haggai is given a message by God to convey to Judah's governor as well as the High Priest and the people in general. The Lord addresses the apathy former Jewish captives of Babylon possessed regarding finishing the work of rebuilding Jerusalem's temple.
[Where Was Israel Taken Captive?]

The negligence and indifference the Jews showed to finishing the temple, per God, had earned them punishment by him (verse 9). Their behavior and unwillingness to place the Lord's will above their own meant that they greatly struggled to provide themselves with basics such as food, shelter and clothing (verses 9 to 11).
God's correction ultimately causes the people to repent and begin rebuilding the temple.
Chpt. 2: Haggai, on the last day of the Feast of Tabernacles, receives another message from the Lord to convey to his people. God addresses the people's discouragement that what they are rebuilding will be inferior to the original temple in Jerusalem.
God encourages Zerubbabel, as well as the High Priest and the people, to be strong in their efforts as he is among them.
Yet now be strong, O Zerubbabel, saith the Lord; and be strong, O Joshua, son of Josedech, the high priest; and be strong, all ye people of the land, saith the Lord, and work: for I am with you . . . (Haggai 2:4).
A little more than two months later Haggai reveals that the Lord still considers them unclean due to their lack of repentance regarding their sins. In spite of this, he promises to bless them due to their newfound determination to finish rebuilding the temple.
Haggai also conveys a message from God to Zerubbabel who is the governor of Judah.