Jump to ContentJump to Main Navigation
Show Summary Details
More options …

Recreational Mathematics Magazine

2 Issues per year

Mathematical Citation Quotient (MCQ) 2016: 0.05

Open Access
See all formats and pricing
More options …

The Triangular Binary Clock

Jörg Pretz
Published Online: 2016-04-14 | DOI: https://doi.org/10.1515/rmm-2016-0001


A new idea for a binary clock is presented. It displays the time using a triangular array of 15 lamps each representing a certain amount of time. It is shown that such a geometric, triangular arrangement is only possible because our system of time divisions is based on a sexagesimal system in which the num- ber of minutes in 12 hours equals the factorial of a natural number (720 = 6!). An interactive applet allows one to “play” with the clock.

Keywords: binary; clock; time; sexagesimal system


  • [1] Pretz, J. “A different way to read o the time - A new idea for a binary clock”, Journal of Recreational Mathematics, Vol. 35(4), 327{330, arXiv:1006.1373v1 [math.HO], 2006.Google Scholar

  • [2] Neugebauer, O. The Exact Sciences in Antiquity, Barnes & Noble, New York, 1993.Google Scholar

  • [3] Wikipedia article. “Babylonia”: http://en.wikipedia.org/wiki/BabyloniaGoogle Scholar

  • [4] Richard A., Carrigan, Jr. “Decimal time”, American Scientist, 305(78), 66, 1978.Google Scholar

  • [5] Wikipedia article. “Decimal time”: http://en.wikipedia.org/wiki/Decimal_time Google Scholar

About the article

Published Online: 2016-04-14

Published in Print: 2016-03-01

Citation Information: Recreational Mathematics Magazine, Volume 3, Issue 5, Pages 5–7, ISSN (Online) 2182-1976, DOI: https://doi.org/10.1515/rmm-2016-0001.

Export Citation

© 2016. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. BY-NC-ND 4.0

Comments (0)

Please log in or register to comment.
Log in