Antiochus Epiphanes
From Landmark
The 42 months refers to the reign of the Antichrist,
specifically, the last half (3 1/2 years)
of the seven-year tribulation.
At the beginning of that time,
the Antichrist will break his covenant with Israel
and set up “the abomination that causes desolation”
Mark 13.14; cf. Daniel 9.27
an act that links the Antichrist to Antiochus Epiphanes,
who similarly defiled the temple.