It’s the eighth shortest book in the Bible and the second shortest in the Old Testament — only 1,131 words in English in two brief chapters.
But Haggai is full of dates. Almost a quarter of its 38 verses are given over to specifying times right to the very day. The book’s five prophecies to four different individuals or groups are each arranged around these dates.
Even readers unconvinced of the inspiration of scripture are unlikely to see such an obvious pattern as accidental or merely a writing tic. They will generally concede the author must be trying to make a point.
It might be worth a few hundred words to try to work out what the point may be.