Calendar family
Invented Reckonings
Deliberate redesigns of time — revolutionary, utopian, commercial and satirical. Most failed; one ran a Fortune 500 company for sixty years.
7 experiments
Decimal Time
French Revolution · 10 h × 100 min × 100 s
Discordian
Erisian parody · five 73-day seasons · years YOLD, from 1166 BCE
French Republican
Calendar of 1793 · equinox-timed (approx.)
Holocene (Human Era)
Gregorian + 10,000 · one count for all of civilization
International Fixed
13 months of 28 days · Kodak ran on it until 1989
Phantom Time
Illig's fringe claim that 614–911 AD were forged (widely debunked)
The World Calendar
Four equal quarters · nearly adopted by the League of Nations