Why is an unexpected spelling HADJ used in the module? From https://sw.wikipedia.org/wiki/Idd_el_Hajj : "Idd el Hajj (pia: Idi el haji, eid el hajj) ni sikukuu ya Uislamu wakati wa mwezi wa Dhul Hijjah ambao ni mwezi wa Hajj. Sherehe hii inatunza kumbukumbu ya sadaka ya Ibrahimu."

This suggests the spelling should be HAJJ. The article continues for several paragraphs with details about this particular holiday.