Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

So, I had a bit of time on my hands to dig around Lexicanum. Sue me. That, or learn how to write dates in Imperial. Who knows, maybe next July 18th you can give your wife of 5 years an Anniversary card commemorating your marriage on 0549005M3.

First off, let's divide up the numbers date into more manageable parts. Let's start with the date above, 0549005M3.

0 is the check digit.
549 is the year fraction.
005 is the year.
M3 is the millenium.

The Check Digit:

This refers to how accurate the date is. Simply put, write a 0 if the event occured on or was observed from Terra. Write a 1 if it occured in the solar system, for example the moon landing.

The Year Fraction:

This is the hardest part. Rather than dividing the year into approximately 365 days like we do, the Imperium divides the year into 1000 fractions. So, "549" indicates the 549th part of 1000 parts of the year.

How do you calculate this? Well, first you need to find which day of the year your event occured on. I gave July 18th of 2005 as my example, which you can find out via this calculator was the 200th day of 2005. Let's split that up even further into hours: multiply that by 24. Now, add however many hours into the day the event occured. Let's assume the marriage took place at 4PM, so that would be 16 hours into the day. 200 x 24 + 16 = 4816.

Okay, so now you know which hour of the year your event occured on. Now to convert that to Imperial Fractions, multiply by what will henceforth be called the Makr Constant. This constant is 0.11407955263862231501532129004257.

4816 * 0.11407955263862231501532129004257 is about 549.40712550760506911378733284227. That rounds down to 549, and you've just calculated your year fraction.

The Year:

This should come to you intuitively. 2005 is 005, 2345 is 345, etc.

The Millennium:

This should also come to you intuitively. We're in the 3rd millennium, 3678 would be the 4th millennium, etc.

Then you just mash all those numbers together, and you have 0549005M3.



Once I get Visual Studio reinstalled, I'll make an application that does all this for you. Until then, nerd away and write Imperial Dates on your friends' birthday cards.

Thanks, this was really handy. I was on the right track, but that whole "check digit" thing was completely eluding me. If you make that calculator, I promise it will see a lot of use as my =][= game continues to unfold.

Shane wrote:Thanks, this was really handy. I was on the right track, but that whole "check digit" thing was completely eluding me. If you make that calculator, I promise it will see a lot of use as my =][= game continues to unfold.

The Check Digit is how "accurate" the date is.

For check numbers 0-1 means that the event happened on Terra or in the Sol system.

A 2 means that the event occurred while someone present for the event was in direct psychic contact with Terra or the Sol system.

A 3 means that an individual or organization present was in psychic contact with a 2 source while the event occurred.

A 4 means that the individual or organization was in contact with a 3 OR 2 source.

A 5 means that the individual or organization was in contact with a 4 source.

A 6 means that the individual or organization was in contact with a 5 source.

7, 8, and 9 class sources are somewhat subjective.

A 7 means that the event in question occured within 10 years of the date listed in the rest of the Imperial date.

An 8 means that the event occured within 20 years of the date.

A 9 class source is special. A 9-class source is an approximated date, and is usually used when recording a date within Warp travel or while on a planet that does not use the Imperial system.

So how do they determine the date locally?

tigonesskay wrote:So how do they determine the date locally?

However they want

This is nice!

It will, however, be even nicer once you've written that aforementioned application!

Yes yes, I'm working on it. I haven't programmed in maybe a year though so I forgot how to do most everything, but it'll probably be done soon-ish.

A (very) rough version is finally done, hooray!

Sorry Mac users, it's in exe format.


Enter the Month/Day/Years as numbers, and the hour in the 24-hour format. (Like, 2PM would be the 14th hour - 12 + 2 - so you would enter 14)

Bug Report!

If the numbers are not a valid range (For Example, Doing Month 13 Day 32, or Month 2 Day 30 ) it still calculates it by whatever formula you are using but it is obviously not a correct date. The Same for setting the month and day to 0 (Hour can of course be 0-23 in range).

Also, it causes a crash if the year is 1 2 or 3 digits (i.e. -999 to 999) adding redundant zeros allows it to work though (i.e. 0056 works but 56 does not).

However, Minus years seem to be working fine

I'll get around to sanitizing the input sometime, yeah.

Thanks for pointing out the thing with the years though - the way the code works is that it lops off the last 3 digits of the "year" entry, adds 1, and outputs that as the millenium. I wasn't thinking of years with not enough digits to do that.

Once it's semi-stable, I think I'll fill up the bottom half of the form with an Imperial-Gregorian Converter.

I miss the 40K Calendar program that was available on Old Dakka.

You could put in any date you wanted and it would give you the 40K version.

One bit regarding the year section, we should be subtracting one

why?
What is 1AD in the Imperial Dating System
1AD is 0 years and xxx year 1000ths into the 1st millennium thus it is cxxx000.M1

and at the other end what would 1000AD be if 1AD = cxxx000.M1
it is 999 years and xxx year 1000ths into the first millennium thus it is cxxx999.M1

based on this what is our current date?
given that we are 18 years and 99 year 1000ths into the 3rd millennium and we are on terra it is 0099018.M3

Holy threadomancy Batman!

Indeed, nigh on ten years. Please don't necro threads.