Above in the explanation, it is mentioned that l'imparfait has no clear beginning or end. But when I attempted the Fill-in-the-blanks Mon jour férié (Passé Composé vs Imparfait), there was a sentence - J’étais encore en pyjama vers 13h, (which is given as the correct answer). Whereas I had written, " J'ai encore été en pyjama vers 13h, and this answer was given as incorrect. But I don't understand, the end time is given here, (vers 13h). So why can't we select Passé composè?