Let's stop counting centuries

Original Article ↗ Hacker News Discussion ↗

Historians and laypeople alike struggle with the convention of numbering centuries (e.g., the “18th century” meaning 1701–1800), prompting calls to instead use terms like “the 1700s,” which align directly with written dates. Commenters debate whether to retroactively introduce a year zero, how to handle ambiguous spans like 2000–2009, and whether such reforms are worth the effort compared to simply learning the existing off‑by‑one rules. The exchange broadens into how language and standards evolve—drawing parallels to metric vs. imperial units and 12‑ vs. 24‑hour time—and whether clarity for non‑experts should outweigh tradition and specialist habits.

Core proposal: use “1700s” instead of “18th century”

  • Many agree “1700s” (or similar) maps more directly to dates people remember (e.g., 1776) and avoids the off‑by‑one mental step.
  • Supporters say centuries are arbitrary cultural bins anyway, so explicit numbers like “1700s” or date ranges are clearer and shorter.
  • Critics find “18th century art” more natural or prestigious than “1700s art,” especially in formal or art‑historical contexts.

Off‑by‑one, year zero, and calendar conventions

  • Recurrent confusion: 20th century = 1901–2000, there was no year 0, AD starts at 1.
  • Some argue we should conceptually insert a year 0 (align with astronomical and ISO 8601 numbering) or treat 1 BC as year 0 retroactively.
  • Others prefer defining the first century as shorter (99 years) or zero‑indexing centuries (“zeroth century”=0–99), though this is seen as impractical or confusing.
  • BC/BCE centuries and calendar switchovers (Julian→Gregorian) are cited as even more conceptually messy.

Ambiguity around “1700s”, “2000s”, and decades

  • In some usage, “1700s” or “1900s” means 1700–1799 / 1900–1999; in others it means only 1700–1709 / 1900–1909.
  • “2000s” can mean 2000–2009, 2000–2099, or even 2000–2999; participants highlight this as a real ambiguity.
  • Proposed fixes:
    • “twenty hundreds” vs “two thousands” for different ranges
    • “aughts” / “noughties” / “ohs” / “20‑aughts” / “00s” / “first decade of the 2000s” for 2000–2009.
  • Some languages (e.g., Finnish, Swedish) naturally use “1900‑century/era”-style terms instead of counting centuries; others lean heavily on Roman‑numeral centuries or idiosyncratic age/decade phrasing, which can also confuse speakers.

Pedantry vs practicality

  • One camp: this is minor; people can learn “subtract 1” and move on; changing entrenched conventions (and all related software, books, habits) is unrealistic.
  • Other camp: small clarity improvements matter, especially for communication and education; conventions can shift via publishers’ style guides and everyday usage without formal reform.
  • Some see resistance as tradition‑defending or elitist; others see the proposed change as over‑pedantic and unnecessary.

Related conventions and analogies

  • Comparisons drawn to:
    • 12‑ vs 24‑hour clocks (midnight/noon ambiguity).
    • Metric vs imperial units, Celsius vs Fahrenheit.
    • Zero‑ vs one‑based indexing in programming.
  • General theme: humans mix ordinals, cardinals, and labels; many such systems are historically accidental yet persist.