EmSai Projects

µDate

µ6820.246 12:30:19 (Sunday, September 7, Year 6820)

µDate (pronounced Uni-Date) is a date standard,
independent of any terrestrial calendar or date systems.
It is my official proposal for UD (Universal Date).
I originally came up with it back in December 1999/January 2000.
And this page fully explains it, source code and a time tool is available in the menu as well!

An example of how µDate looks can be seen at the top of this page,
which is showing the date and time this page was cached.

The concept behind µDate was that the current
Earth based systems are just that, Earth based.

A new system is needed if the human race continues to expand into space and beyond,
and for that to be successful we can not rely on a system that is based on a
rotating planet that rotate slower and slower over the years.

Also, a season based calendar serves no purpose either, again a planetary based system.
And on other planets such seasons are different, and years as well, and days.
And in space itself there are no such things at all.

µDate thus also adds a virtual "calendar" which has years,
months, weeks, and days.
Although µDate itself only have years and days.

µDate has no leap years/days/seconds,
it bases itself on JDN (Julian Day Numbers) and TAI (International Atomic Time).
JDN + TAI is mostly used by astronomers, you may be more familiar with UTC
(Universal Time Coordinated, aka GMT) which is a variant of TAI adjusted against Earth's rotation (UT1),
and includes correctional leap seconds that is scheduled now and again.
And is the variant that pretty much everyone in the world synchronize their clocks too.

µDate was also designed to be a supplement to JDN and TAI,
thus eliminating the need to use MDJ (Modified JDN) that was created
with the only purpose being to shorten the very long JD numbers.

With µDate MDJ is no longer needed, nor JDN (directly at least).
µDate can replace MDJ and serve as a manageable alternative to JDN,
and as a supplement to UTC/TAI, not to mention being unbound of planetary dependencies.

µDate is easily computable by hand, and computer math friendly.
If µDate is accepted as a official standard, it is suggested it is renamed
to UD (Universal Date) but still continue to use µ as a informational identification in front of dates.

So what is µDate calculated from, and how?
If you looked at the example source and are still clueless, sorry, it's a older code and needs a full rewrite some time soon.

Grab your calculator! Take the JDC (Julian Day Number civil) divide by 360 (rounding down to nearest integer),
then take this result multiply by 360 and use this result to subtract from the JDC.
This should give you the number of days beyond µYear,
and you already have the years from the first math obviously.

Please take care to note that µDate count "years and days passed since",
rather than the day in progress like the Gregorian calendar does.
So µ6816.030 indicate that (6816*360)+30 days has "passed" since 0 (zero).
This means when you celebrate 6816, it truly is 6816 years since 0 (i.e. the beginning).

Alternatively you can use JDN (Julian Day Number astronomical),
just remember to compensate for the .5 day.
Because µDay starts at 00:00:00 and ends at 23:59:59,
just like UTC, so using JDC as source if preferable where possible.

A µDay is 24 hours as already mentioned.
And as far as µDate goes that's it for the standard.
But since we are habitual creatures, and thinking of a year
divided into 0-359 is kinda odd (although very precise),

µDate also has a optional µMonth and µWeekday standard,
this is only intended for human display, and not for calculations, use µDate for that instead. A µMonth is 30 µDays, there are 12 µMonths in a µYear,
and uses the same month names as in the Gregorian calendar.
A µWeek is 7 days, the weekday names are the same as in Gregorian calendar.

There is a obvious year wrap issue with weeks,
but same issue exist with the Gregorian calendar, so nothing new here.
The nice thing though, is that using basic math alone,
you can easily calculate the current month name or weekday name directly from JDC.
Something that requires more extensive maths and tables with existing calendars.

That's it really, that is all there is to it about the µDate standard,
I'm really itching to call it UD (Universal Date) so it's nicely paired with UT (Universal Time),
but hopefully the computer and scientific community accept µDate and later call it UD,
when a proper standard is made, maybe someone would like to help me by out by drafting a RFC? Contact me!

Just a quick recap:
Universal Date consist of 360 days per year, 24 hours per day, 60 minutes per hour, 60 seconds per minute,
7 days per week, 30 days per month, 12 months per year.

Math to calculate Universal Date: years=JDC/360, days=JDC-(years*360), hours&minutes&seconds=TAI.

Universal Date is displayed as: µ6816.031 11:31:54
If µ can not be displayed, use: UD 6816.031 11:31:54

See the source for a quick implementation in PHP,
or fool around with the µDate time tool.
it uses the server clock so is not atomic UT1 time accurate sadly!