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In history the Romans didn't count their days of a month not by adding each day extra. But instead of that they used three moments in a month, Kalendae, nonae and Idus. And from those days they counted back. Now in the 4th century Constantine introduced with his new christian religion also a new kind of dating. The 8 days week was changed in a 7 days week. And also the names of the days changed from A t/m H to the planetairy names of the day, like the roman languages has at the moment.

But was that also the day that they start counting like 1,2,3...28,29,30 of the month?

marked as duplicate by Pieter Geerkens, Mark C. Wallace, Anaryl, Fred, Community Apr 3 '16 at 11:04

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