Mathematical manipulation of dates and times continues to plague us. It is true that the periodicity of the solar day and year don’t fundamentally lend themselves to a base-10 construct, but is there no middle ground? Consider the following as a starting point for discussion:
Currently, we have divided the solar day into 24 x 60 x 60 = 86,400 seconds.
I propose a day of 10 hours x 100 minutes/hour x 100 seconds/minute = 100,000 seconds/day.
This redefinition of the second would require a move from 9,192,631,770 Cs periods to 7,942,433,849.28 Cs periods. A prefix or alternative name, such as dSeconds (decimal seconds), could be used to disambiguate the redefined seconds (ds), minutes (dm), and hours (dh). A periodic adjustment, similar to leap seconds and leap years) could be used to round the above number to an even number of Cs periods.
Writing the time could take the format H-MM-SS (0–9 dh; 00–99 dm; 00–99 ds). Why the dashes? For disambiguation during the transition, and consistency when written alongside the date.
The next natural step would be a 10-day week. This divides the year into 36.5 weeks, and allows us to write the date using a year followed by a decimal representation of the week number (in the format YYYY-WW.D, with days running 0–9).
For example, 2015–33.9 would be today’s date. Writing the full date and time would take a form such as 2032–08.3–7–73–86.
I realise it’s imperfect to have a fractional week at year’s end. But then again, maybe it’s not so imperfect. Consider the possibility of a universal 5-day holiday, observed worldwide, to ring in the new year. A festival of renewal across all cultures. I quite like the idea. Holidays around the new year are already the norm in many places.
How should we divide up our new week?
Currently, those who are fortunate enough to work only 5 days/week work 71.4% of days (discounting holidays, which vary by locale).
I propose a standard work week of 7/10 days, which represents a slight reduction in working time (to 70%), but I believe this would be more than outweighed by the increased productivity of fewer weekends and longer periods of contiguous work between them.
When should we start our redesigned year?
The obvious options are the equinoxes and solstices. Solstices are attractive, giving an ABA pattern to day length, but the opposite hemisphere would experience a BAB pattern, which means that half of the world would be celebrating their new year during the longest days and half would be celebrating during the shortest days. I prefer choosing an equinox instead, with a medium day length in both hemispheres during the new year. Arbitrarily, I would propose the Northward equinox as the start of the year, roughly 20 March by the Gregorian calendar.
What about the names of the days?
Why complicate matters? Use the numbers: “Day 0,” Day 1,” and so on.
What about months?
Eliminate them. They serve no purpose.
What about time zones?
Eliminate them. We already have universal time in the form of UTC. Critical systems have adopted it but the broader public has been resistant to the change. The new base-10 system would offer only universal time. We would learn to ask what time people wake up in a particular country, rather than asking what time it was in that country. We would know what time it was everywhere by simply looking at the clock.
What about Daylight Saving Time?
Burn it with fire.
What about my six-figure A. Lange & Söhne watch?
I do feel a bit badly about that. But clocks have evolved before — they can do so again.