Reminds me this cool episode of 99% invisible[1] where they talk about calendar design, in particular, Kodak company used a 28-day/13 month design calendar until the 70s and it turns out it was beloved by teams who were doing a lot of forecasts.
1: http://99percentinvisible.org/episode/the-calendar/
When I see how tough it is to move to the metric system in the US, I'm not quiet sure we'll ever see such a change any time soon tho!