It's not a U.S./Europe dichotomy. The first day of the week being Sunday is a Judaeo-Christian, and Islamic, thing. For countries with these as official relig

It's not a U.S./Europe dichotomy. The first day of the week being Sunday is a Judaeo-Christian, and Islamic, thing. For countries with these as official religions you will find that offically Sunday is still the first day of the week for many purposes. For example: In the U.K., officially still Protestant, a week for the purposes of statutory sick/maternity/paternity pay or national insurance begins on a Sunday. Sunday trading legislation was talking about weeks commencing on Sunday as recently as 1950. * http://www.legislation.gov.uk/uksi/2014/1640/article/2/made http://www.legislation.gov.uk/uksi/2014/1640/article/2/made * http://www.legislation.gov.uk/ukpga/Geo6/14/28/section/22/enacted http://www.legislation.gov.uk/ukpga/Geo6/14/28/section/22/en... If you think that millennia-old traditions, which you can still find observed in Europe if you look, are weird then academic weeks beginning at noon on Wednesday, examples of which can also be found in both the U.S. and Europe, will probably blow your mind.