Some people believe that in many computer systems it is not convenient to name files according to a date of Georgian calendar. Personally, I prefer the system I introduced myself (see post №12 (16.09.2013), "File Nomenclature Unicode"). Briefly, it is the idea of naming the file in the following fashion: yyyy.mm.dd.hh.mm.ss Geographical location Description. After naming the files that way, the system will automatically sort them chronologically.

However, some debates on the topic have occurred. I offered to name files differently for chronological sorting when dividing the time frame on either just years, or just month, or just days. Such system may not be convenient for all, but if for some reason the files must be sorted by months or days only, it may be a better idea to name them properly. The idea is to count months from January of the year 1 of the Common Era, and days from the 1st day of January 1AD. In that fashion, January of year 1 can be simply named 1, February of year 2 as just 2 and so on, so February of 2017 we may name 24194, not 2017 02 as offered in the beginning, and March of 2017 as 24195, not 2017 03. It is easy to calculate the desired month for its nomenclature. For example, one needs to name a file created in January 2017. To do that, he has to multiply 2016 & 12, being 2016 years that have passed since 1AD and 12 month in each year, and to add 1 to this number, i.e. January. So 2016x12+1=24192+1=24193. If one desire to know what the month of April 2017 will be, he will have to change the above formula by replacing 1 with 4 (since April is the 4th month of the year). That way, the number will be 2016x12+4=24192+4=24196. For the convenience of the reader, I decided to make a table of the numbers of months. For example, to calculate what number December 2016 was, I have to multiply 2015 and 12 (number of years passed times number of months in each year) plus 12 (December is the 12th month of the year), or simply calculating the quotient of the numbers 2016 and 12, which will be the same number. So 2015x12+12=2016x12=24192. For each of the following months I simply added 1 to that number, so January of 2017 was 24192+1=24193, February of 2017 is 24194, etc. For the previous months I substracted 1, consequently:

January 1 -----------------1

February 1 ----------------2

March 1 -------------------3

...

December 1 -------------12

January 2 ----------------13

February 2 ---------------14

...

November 2016 --- 24191

December 2016 --- 24192

January 2017 ------ 24193

February 2017 ---- 24194

March 2017 ------- 24195

April 2017 --------- 24196

May 2017 ---------- 24197

...

Such system is good, however, only for dating in Common Year. As well as the previously offered, there is no use of it for the dates before Common Era.

As for the days, the calculation becomes a little more confusing but not less exact. In numerating dates starting 1 January of year 1, the table will be filled in a similar manner:

1 January 1 ------------------- 1

2 January 1 ------------------- 2

3 January 1 ------------------- 3

...

30 January 1 ---------------- 30

31 January 1 ---------------- 31

1 February 1 ---------------- 32

2 February 1 ---------------- 33

3 February 1 ---------------- 34

...

30 December 1 ----------- 364

31 December 1 ----------- 365

1 January 2 ---------------- 366

2 January 2 ---------------- 367

3 January 2 ---------------- 368

...

26 February 2017 ---- 737386

27 February 2017 ---- 736387

28 February 2017 ---- 736388

1 March 2017 --------- 736389

2 March 2017 --------- 736390

...

The formula for calculating a particular day is composed in a similar manner. Let's say we need to figure out what number will be given to today, 27 February 2017. First of all we have to calculate how many days have passed during the previous years, & then add the number of the days already passed in 2017. There are 365 days in each year, so 2016x365=735840. But how do we count the number of years in which the day of 29 February occurred? Very simply. As we know, leap day falls on every 4th year, so in the years 4, 8, 12, 16, 20, ..., 2008, 2012 & 2016 (any year divisible by 4) the leap day occurred. The exceptions were the years divisible by 100 but not divisible by 400. So the years 100, 200, 300, 500, 600, ..., 1500, 1700, 1800 and 1900 did not contain the leap day while the years 400, 800, ..., 1200, 1600 & 2000 did. So 31 December 2016 was not simply the 735840th day of the Common Era (2016x365=735840). In order to figure that out we have to add the number of leap years to 735840. Apparently, there were 489 leap years starting the year 4 and counting 2016. So 735840+489=736329, which was 31 December 2016. Consequently, 1 January 2017 was the 736330th day of the Common era, and today is 736387 counting that way.

It may long be debated how convenient it is to name files and dates those ways, the answer is one: it depends. In any ways, it might be fun to know that today is the day 736387 of the Common Era.