The UFO labour union said the strike would begin on Tuesday, but they were still discussing what time it would begin and which airports it would affect.
But this action is expected to have a wider impact than Friday's walkout.
That action lasted eight hours and mainly affected Europe's third-biggest airport Frankfurt, forcing the airline to ground 190 of 360 flights.
The strike was called after Lufthansa's management failed to come to an agreement with employees over salary and working conditions.
UFO, which represents some two-thirds of Lufthansa's 18,000 cabin crew members, is seeking a 5.0-percent pay increase for cabin staff for 15 months, backdated to January this year after three years of wage freeze.
It is also opposed to the use of temporary cabin staff in Lufthansa aircraft.
According to a Lufthansa passenger traffic staff, Peter Gerber, the airline had offered a salary hike of "about 3.5 percent."