There have been many comments on CR4 about how the US lags behind the rest of the world in changing to the metric system, a system of decimal units, but no one is considering how old and archaic the worldwide calendar is, and how confusing it is to people who have to schedule work, projects, etc. I mean, really, 7 days in a week, 4 weeks in a month (except that is only 28 days and only one month has only 28 days!), 12 months in a year! Even if you do away with months, we still have 52 weeks, with an extra day or two every year! Why it's as bad as the old English coin/currency system! (Pence, shillings, farthings, crowns, pounds)
Well, as long as we want to measure everything in decimal units, why not change the calendar? I mean, come on, Julius Caesar and Pope Gregory have been dead for hundreds and hundreds of years. They really won't care.
We already have some decimalization, decades, centuries, millennia. Isn't it about time (no pun intended) we decimalized the year? I mean, what is so sacred about a seven-day week? (Oh, yeah, creation and all that...)
Realistically, and astronomically, we need to keep the 365 (and 1/4 or so) days per year, since our circadian rhythm cycles are based on day/night cycles and the orbit of the earth dictates the seasons, but why do we need Months, at least the ones we have now? They are never the same number, you can't get a whole number of weeks in any of them except February, and the lunar cycle does not even match up!
How about 36, 10-day weeks. Work/school for 7 days, then off 3 (3-day weekends!). This gives a work-time "duty cycle" of 70%, as compared to the old 5 out of 7 for 71.4%. Of course that leaves an extra 5 days, which would become international holidays, and be placed at the end of the year, giving everyone the time off they usually take between Christmas and New Year's anyway. This would become known as "Halfweek" and would be a time of international peace and goodwill, since it falls on or near major holidays. Traditionalists will still mark holidays by the old calendar, so December 25 would be the second day of the last 3-day weekend before Halfweek. Everyone would be happy they don't have to work, except of course those who work in vital services like hospitals, airlines, hotels, and Wal-Mart. Every 4 years "Halfweek" would get an extra day, just like in Leap Year now.
Months, if your really must use them, would now be EXACTLY 30 days, that is 3, 10-day weeks, so there would be no more need to memorize "Thirty days hath September, April, June, and November....." However I would prefer just to use the calendar week number, as many do in planning projects.
When I was a Project Engineer for a machine tool company, we used the Master Schedule from our German plant for co-ordinating the machine design and build schedule with our customer. The Gantt Chart had the weeks labeled as "KW 1, KW2, KW3" etc. starting with the first week of the project. The customer asked us what KW meant. My boss decided to tell them it was "Key Week", because of how important it was. Later we found out that it was "Kalendar Woche", or Calendar Week in German!
I think this whole thing makes more sense than the Metric System setting a length of measure as 1/40,000,000 of the polar circumference of the Earth, then finding out that is not even accurate, but by then it was too late to change and the standard became an arbitrary distance between two scratches on a metal bar!
Oh, I see, in checking my figures in the Wikipedia for the measure of the meter that my proposal is very similar to the French Republican Calendar used in France between 1795 and 1802.
Well, maybe it did not catch on in the rest of the world back then, but a good idea is worth trying more than once, isn't it?
The French even went so far as to decimalize the day, hours, minutes, and seconds, but I think that would cause for more problems than it would cure. Daily timing is critical and there is a lot that depends on our clocks being accurate and relatively synchronized, especially now that clocks and watches can be updated by the atomic clock broadcasts several times a day to correct even a second of inaccuracy.
The calendar is relatively simple. People throw them out every year anyway! It would be simple to pick a year and just start fresh! We don't even need to change the names of the months! We would however need names for three more days in each week. Let's assume we start the work week with Monday as usual. Then the same five days would follow, T,W,Th, F, Saturday, all work days. The last workday could be Oneday (as in One day to go before the weekend!), then the weekend could be, Freeday (day to do whatever you wanted, shopping, adult education, community service, charitable work, hobbies, etc.), Funday (for relaxation, sports, family outings), and finally Sunday as a day of prayer, family socializing, or meditation for the Christian majorities in many countries, including the US, Latin America, Europe, and Commonwealth nations. Moslem, Buddhist, Hindu, and other non-Christian nations would have to decided if they wanted to us Sunday or another week-end day as their religious observance day. Of course, with fewer Sundays in a year, the services would have to be longer to make up for the lost time! 
Think this could work? Any other suggestions?