en_tn/dan/12/11.md

an end is put to the regular burnt offering and the abomination that causes complete desolation is set up

The king of the north is the one who stops the temple sacrifices. Alternate translation: "the king of the North puts an end to the regular burnt offering and sets up the abomination that causes complete desolation" (See: rc://en/ta/man/jit/figs-explicit)

the abomination that causes complete desolation

This refers to an idol that will make the temple desolate, that is, that will cause God to leave his temple. See how you translated this in Daniel 11:31. Alternate translation: "the disgusting idol that will cause God to abandon the temple" or "the disgusting thing that will make the temple unclean" (See: rc://en/ta/man/jit/figs-idiom)

1,290 days

"one thousand two and hundred ninety days" or "twelve hundred and ninety days." Here "days" refers to a period of time. Most commonly rendered as days, but can also imply years. (See: rc://en/ta/man/jit/translate-numbers)