When did the civilized world adopt the 52 weeks calender.

Answer 1

As many other cultures did,the lsraelites kept time by two calenders:the civil calendar of week days,which was used to note market days,loan dates,and other functions,and the calendar of moonlight,or religious calendar,used for special religious festivals(lrwin,61)
Due to the extra day(s)at the end of the 52-week year,both the year and each of the four seasons began on the first day of the week and ended on the last day of th week.The jews later modified this system by making extra day(s)a part of the week As a result,the first year would now begin on the first day of the week,the next year on the second day of the week,the third year on the third day and so on for common(365day)years."After a leap year the starting day jumped over a week day;the third-day beginning of that year,for example would be followed by a fifth-day beginning for the next year.it was from this leaping over of a week day that leap year got its name(lrwin93)