The datum shift between two particular datums can vary from one place to another within one country or region, and can be anything from zero to hundreds of meters (or several kilometers for some remote islands).
Datum shift jir issin datum tan izlay s edag s iyyan daɣ addawla megh rejion iyyat addobat ad eqqil harat ghur bannan har timad n metir tan ( meɣ metir tan ajjotnen i island tan wi ajjujnen)