These common nouns can function as adverbs of time when the sentence uses them to locate or measure an action.
WordMeaningWordMeaningثَانِيَةٌsecondدَقِيقَةٌminuteسَاعَةٌhourيَوْمٌdayأُسْبُوعٌweekسَنَةٌ / عَامٌyearقَرْنٌcenturyدَهْرٌa long age
The dictionary form is shown here; its ending changes according to its role in a sentence.