The union, which represents about 37,000 train drivers, conductors and shunters, said the strike would kick off from 1600 GMT, and primarily hit freight traffic.
GDL demands a pay increase of 5 percent for workers, as well as a shortening of their work week to 37 hours from 39.
News of the strike comes three days after pilots at Germanwings, the budget carrier of flagship airline Lufthansa , staged a six-hour strike in a dispute over a pension scheme, disrupting domestic travel.