While spending a summer in the city of Tunis back in the early 70s, I recall the Tunisians using a unit of time called the "دْرَج" (drej) and, if I remember correctly, it denoted a period of time equal to 20 minutes (corresponding to the Moroccan "ثُلْث" (tult). E.g. "خمسة ودرج" would mean 5:20, "خمسة ودرجين" would mean 5:40, and "خمسة غير درج" would mean 4:40, etc. Just recently I met a student from Sfax who told me that دْرَج actually denoted a period of 5, not 20 minutes. Is my memory faulty, or has there been a change in meaning in the last 40 years, or is there maybe a difference in usage between Sfax and Tunis? I'm thinking it's more likely that my memory has failed, but would appreciate information from anyone who is a native speaker of the Tunisian colloquial. Thank you.