I got a bit of a headache when I saw that B.C.E dates are displayed on the slider like: 12-01--4. Four years before the Common Era, aka &quot;-4&quot;... hah! It seems ISO 8601 actually tries to solve this problem:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;ISO_8601#Years" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;ISO_8601#Years</a>