God commanded Israel to observe 3 main feasts in the year. The 3rd and final feast was the feast of tabernacles/ingathering, which was to be held in the 7th month (15th day to the 23rd day). After the final feast (tabernacles) was held, the Hebrew calendar year still had FIVE MONTHS remaining (8th, 9th, 10th, 11th, & 12th).Interesting that five months is the figure God uses to describe Judgment Day:

Revelation 9:5 And to them it was given that they should not kill them, but that they should be tormented five months:

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