For ease of use, left-handed people using right-handed calendars should go back in time.
Left-handed calendars are baked! This is a two-timeline calendar, one side for left-handers and one side for right-handers. A new layout means left-handers get to cross off dates forward in time without smudging,
while right-handers also avoid smudging but actually log time backwards.
Ambidextrous people can keep using the left over gregorian calendars.
This will create the ultimate "arms" race - which timeline will the most innovation and breakthroughs be recorded on for humanity? A new holiday is created for when dates align, Hand-Holding Day ----
Achievements by both hands in the same 'ambidextrous year' are recorded as:
1998 RH / 2038 LH (2038 A.D. (AmbiDextrous))
1952 RH / 2084 LH (2084 A.D.)
1907 RH / 2129 LH (2129 A.D.)