BlackFriday2020: Has human history ever ‘lost’ a day? How do we know Friday is actually Friday? Could we have lost any when major calendar systems changed?

Has human history ever ‘lost’ a day? How do we know Friday is actually Friday? Could we have lost any when major calendar systems changed? – QuoraPlease enable Javascript and refresh the page to continue

Fonte: https://www.quora.com/Has-human-history-ever-lost-a-day-How-do-we-know-Friday-is-actually-Friday-Could-we-have-lost-any-when-major-calendar-systems-changed