This is the 403rd most frequent Finnish word.
ehti
"Ehti" means "had time" or "managed (to do something)."
Here, 'ehti' is used to indicate that the subject successfully accomplished reaching the bus in the time available.
Hän ehti bussiin ajoissa.
He made it to the bus on time.
In this context, 'ehtinyt' conveys the inability to manage or find time to see the end of the movie.
Minä en ehtinyt nähdä elokuvan loppua.
I didn't manage to see the end of the movie.
'Ehdin' here reflects the speaker's belief that there is enough time to complete the action before the next scheduled event.