Until 1975, the week in Germany traditionally started on Sunday, rooted in Jewish-Christian heritage. Since January 1, 1976, Monday has officially been the start of the week due to the introduction of DIN standard 1355-1. This change represents a cultural and normative shift, positioning the unpopular Monday as the first day.
In Germany, the week started on Sunday at 0:00 until the end of 1975 and ended on Saturday at 24:00, aligning with Jewish-Christian tradition. The Bible states in Exodus 23:12: "Six days you shall labor, but on the seventh you shall rest." The Sabbath as the seventh day made Sunday the first workday; Monday was called "Yom sheni" in Hebrew, the second day.
On January 1, 1976, the German Industry Standard DIN 1355-1 took effect, declaring Monday the official start of the week. This shifted Wednesday from the exact middle of the week. As late as 1949, the Brockhaus Encyclopedia described Monday as the second day of the week. Roman Emperor Constantine had already declared Sunday a day of rest on March 3, 321, yet calendrically, Sunday remained the start—in countries like the US, Canada, Portugal, Brazil, and India.
Mondays are unpopular: A YouGov poll from March 2021 found only 1 percent of Germans like them, tied with Tuesdays. Colloquially, "Monday piece" refers to defective products, and the "Monday effect" denotes poorer stock market performance. Songs like "I Don’t Like Mondays" by the Boomtown Rats (1979) reflect global frustration; the track is based on Brenda Ann Spencer's rampage on January 29, 1979, in San Diego, where she said: "I don’t like Mondays." Two died, nine were injured.
Statistically, Monday accidents cluster: 18 percent of all accidents in Germany occur then, compared to 8.5 percent on Sundays. Expert Milad Haghani from the University of New South Wales notes more work, traffic, and heart attacks due to the weekend transition. Leipzig University researchers (2021) explain: "The contrast between Sunday and Monday can lead to the first day of the workweek being perceived as the worst day of the week." The "Sunday blues" also stresses, as psychologist Bettina Löhr says: "Just the thought of work can trigger a stress response."
In the GDR, Monday was the week start since 1949, fitting its atheistic work ideology. The 1989 Monday demonstrations in Leipzig contributed to the fall of SED rule. Honoré de Balzac is credited with: "Monday is only bad if you let it be."