This is the 419th most frequent Croatian word.
proteklih
"Proteklih" means "past" or "previous" in English.
The word 'proteklih' is used here as an adjective modifying 'nekoliko tjedana' to indicate a duration in the past.
U proteklih nekoliko tjedana, radili smo na novom projektu.
In the past several weeks, we have been working on a new project.
Here 'proteklih' describes 'godina', denoting a set period of years in the past.
Tijekom proteklih godina, mnogo se toga promijenilo.
During the past years, many things have changed.
In this case, 'proteklih' modifies 'dana', reflecting a specific timeframe from recent days.