How were months different a thousand years ago?

Answer 1

All the months of the Julian calendar in use 1000 years ago had the same names and the same number of days per month as the Gregorian calendar we use today. Also the numbering of the years based on the time of Jesus started about 1500 years ago and has been popular for the past 1200 years.

The only differences were (1) by 1013 the error in the Julian calendar had already accumulated to six days, so seasons that normally start on the 21st were starting on the 15th instead, and (2) January 1st was not the only New Year's Day like it is today among users of the Gregorian calendar. Different countries started the year on different dates. The date 1000 years before Saturday, February 2, 2013 was Tuesday, January 27, 1013 (Julian calendar, with that six-day difference), but many would write it as Tuesday, January 27, 1012 (considering the beginning of 1013 to be in March).