More than two million people in the country said they worked either regularly or always at weekends, the Süddeutsche Zeitung reported on Monday, citing figures released in response to a parliamentary question.
And the number of people working shifts rose from 4.8 million in 2001 to six million in 2011, the figures said. Most shift workers are to be found in the healthcare professions, engineering and sales, the paper said.
The physical and psychological risks of working irregular hours are well known, and were even noted by the government along with its release of the numbers showing an increase in those working so.
The number of people working nights reached a high of 3.3 million in 2001, a level which had not previously been seen since 2008. Between 2001 and 2004 the figure was around 2.5 million.
Nearly two million people - 1.92 million - worked for more than 48 hours a week during 2011. In 2001 just 1.56 million people worked so long, representing a growth of 23 percent over the decade. Teachers, engineers and managers were the most likely to be staying late at their place of work.
Karl Brenke, job market expert at the German Institute for Economic Research in Berlin told the Süddeutsche Zeitung the growth of abnormal working times was down to a number of factors. Highly qualified managers were often expected to remain in the office long into the evenings, and to be available at weekends.
But shops were also open for longer, stretching the working day for workers, while competition among logistics firms has been leading to increased pressure for truck drivers to be available around the clock, he said.
Jutta Krellmann, spokeswoman for the leftwing party Linke, which submitted the written question, said the figures were alarming. "The psychological stress is a ticking time bomb in the working world and has to be stemmed," she said.