Som er den første dag i ugen?
Mandag
Sunday
"Mandag skal identificeres som kalenderdag i en kalenderuge, og efterfølgende kalenderdage i samme kalenderuge skal nummereres i stigende rækkefølge til søndag (kalenderdag )." Yderligere diskussion: UK National Physical Laboratory: "Hvilken er den første dag i ugen? Og hvilken er årets uge 1? (FAQ - Tid)": |http://www.npl.co.uk/science-technology/time-frequency/time/faqs/which-is-the-first-day-of-the-week-and-which-is-week-1-of-the-year-(faq-time) (Arkiv her: https://archive.is/SMEAx)
Monday
"Monday shall be identified as calendar day  of any calendar week, and subsequent calendar days of the same calendar week shall be numbered in ascending sequence to Sunday (calendar day )." Further discussion: UK National Physical Laboratory: "Which is the first day of the week? And which is week 1 of the year? (FAQ - Time)": |http://www.npl.co.uk/science-technology/time-frequency/time/faqs/which-is-the-first-day-of-the-week-and-which-is-week-1-of-the-year-(faq-time) (Archive here: https://archive.is/SMEAx)
Sunday