Spring from March to May and Fall from Sept to November.

Now, if the Gog Magog attack on Israel happens this March, then there would be enough time for the Russian Army to be devoured on the mountains of Israel between March and May.

If the Russia army isn't fully mobilized until Summer, then they will be devoured during the fall migration from Sept-November, IF the Gog Magog war is to happen this year. WOW, this is so cool.