Beastmaster 2: Through the Portal of Time

The witch Lyranna opens a portal so Dar's half-brother Arklon can steal a neutron detonator from present-day Los Angeles, and Dar follows; a long middle stretch is sword-and-sorcery characters loose in 1991 LA before the story returns home. Despite the title, sources describe the portal as trans-dimensional and LA as an alternate world rather than Dar's future, so the temporal content is the time-travel framing and the pre-modern culture clash rather than movement through time. The crossing is substantial but not established as temporal, so the score drops from 5 to 3.

Promoted as time travel, but the synopsis describes passage from a fantasy world to Earth; whether this is temporal displacement or only interdimensional travel remains uncertain.