Public transport and schools are to be the main focus of the strikes.
It was not possible to predict in advance how much support the strike call would actually receive.
In Paris, for example, the metro was to run without restrictions, but disruptions were announced for buses and suburban trains.
Regional restrictions were feared in rail traffic.
Traditionally, there are nationwide protests in France in the autumn, when everyone is back from their summer holidays, about social grievances.
However, due to billions in aid and an energy price cap, inflation in France is currently much lower than in other European countries.
The pension reform, which aims to raise the retirement age from 62 to 64 or 65, is more controversial.
For many people in France, this is a like a red rag to a bull.
The trade unions and the opposition are divided in their protest against the government at the moment.
While the trade unions are demonstrating on Thursday, the Left Party, Socialists and Greens have called for a “march against expensive living and doing nothing in the climate crisis” on October 16.