Mental Floss 2014-12-19T06:36:34+00:00 2009-08-07T14:10:10+00:00 2013-06-04T14:41:11+00:00 Why is 10:10 the Default Setting for Clocks and Watches? Matt Soniak

Reader Humaira writes in, "I have always wondered why clocks, watches, timepieces etc. always say (roughly) 10:10 before you set the correct time? If you go in a store selling any kind of time-telling device, that is the default factory setting. Why is that?!!"

First things first, let's get the myths out of the way. There are plenty of people out there who think that clocks in advertisements and in-store displays are set this way to memorialize Abraham Lincoln/John F. Kennedy/Martin Luther King Jr. because that was the time at which they were shot or died. In reality, Lincoln was shot at 10:15 p.m., and died the next morning at 7:22 a.m., JFK was shot at 12:30 p.m. CST and was pronounced dead 1 p.m. and MLK was shot 6:01 p.m. and pronounced dead at 7:05 p.m.

Another theory has it that 10:10 was the time that an atomic bomb was dropped on either Nagasaki or Hiroshima, and that the setting is in memory of the casualties. The Fat Man bomb was actually dropped on the former at 11:02 a.m. local time and the Little Boy on the latter at 8:15 a.m. local time.

grandfather-clockThe real reason for the setting? Aesthetics. The 10:10 position gives the clock or watch a number of benefits:

• The hands are not overlapping, so they're fully and clearly visible and their styling can be admired.

• The arrangement of the hands is symmetrical, which people generally find more pleasant than asymmetry, making the product more appealing to customers.

• The manufacturer's logo, usually in the center of the face under the 12, is not only visible but nicely framed by the hands.

• Additional elements on the face (like date windows or secondary dials), usually placed near the 3, 6, or 9, won't be obscured.

According to the folks at Timex (who set their products at 10:09:36 exactly), the standard setting used to be 8:20, but this made the face look like it was frowning. To make the products look "happier," the setting was flipped into a smile (occasionally, you'll still see the 8:20 setting on some clocks or watches where the manufacturer's logo is at bottom of the face above the 6).

August 7, 2009 - 6:10am