We can kick off this new calendar and gradually migrated over :), some cultures around the world already use multiple calendars, their traditional ones (Lunar c

We can kick off this new calendar and gradually migrated over :), some cultures around the world already use multiple calendars, their traditional ones (Lunar calendar, Indian calendar etc) and Gregorian Calendar. I am also thinking once we've gone multiplanetary (going to Mars), we might need a new calendar system.