Perpetual Fortnight Calendar

[Irv Bromberg]

On 2012 Jan 26, at 08:37 , Karl Palmen wrote:

This leads to the idea of a fortnight calendar in which each year has 26 fortnights and a leap week is inserted once every 147 fortnights (5 years and 17 fortnights).

On 2012 Jan 26, at 08:52 , Sonny Pondrom wrote:

What do you think about the perpetual Fortnight calendar shown below?

Irv replies:  Sonny's idea of designating the 26 fortnights by the 26 capital letters of the English alphabet is attractive.

This is good.

I had considered the idea of a fortnight calendar, but rejected it because it would be awful to come up with 26 fortnight designations that would be easy to remember.

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

Of course Sonny ignored the thread's focus on it being a leap week calendar, so I'll ignore his "0" and "8" days.

The use of the capital letters to designate the fortnights has the advantage that only a single character is required to specify the fortnight, and no date separators are necessary.

Since Karl's idea places the leap week at an exact interval, it can occur anywhere in the year, and could be designated by the lowercase letter of the fortnight that preceded it.

This is akin to the designation of the leap month in the Chinese lunisolar calendar.

Thus the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Division into quarters could ignore the leap week, wherever it is positioned (at intervals of 294 weeks).

First quarter = A through first week of G.

Second quarter = second week of G through M.

Third quarter = N until first week of T.

Fourth quarter = second week of T through Z.

The moving leap week over the long term would affect everybody's birthdate equally, so it is fair to all.

-- Dr. Irv Bromberg, University of Toronto, Canada

<http://www.sym454.org/>

[Irv Bromberg]

On 2012 Jan 26, at 13:01 , Sonny Pondrom wrote:

Now lets say that another phone company wants me to join them because they also have the same price and provide quicker service.  However, I may keep my old phone as before.   Do I go with the one that lets me keep my old number or go with a new one?

Answer:  Find a company that has an easy phone number to remember.    

Not in my books!  The last thing I'd want is to make it any easier for people to reach me by telephone!  And voice mail?  P-L-E-A-S-E switch it off!

[Irv Bromberg]

On 2012 Jan 26, at 13:01 , Sonny Pondrom wrote:

Now lets say that another phone company wants me to join them because they also have the same price and provide quicker service.  However, I may keep my old phone as before.   Do I go with the one that lets me keep my old number or go with a new one?

Answer:  Find a company that has an easy phone number to remember.    

Not in my books!  The last thing I'd want is to make it any easier for people to reach me by telephone!  And voice mail?  P-L-E-A-S-E switch it off!

On 2012 Jan 26, at 17:14 , Sonny Pondrom wrote:

You lost me, Irv.  How does your telephone response relate to the Leap day hyperbole? 

That is exactly my point!  Your telephone leap day hyperbole is irrelevant!

[Irv Bromberg]

On 2012 Jan 26, at 11:48 , Irv Bromberg wrote:

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Irv adds:  Actually D, if numeric, has to have two digits because a fortnight has 14 days.  A single digit could be used for the leap week, but that is not a reliable way to distinguish the leap week because people might omit the leading zero of D for the first week of fortnights.

[Brillig]

Dear Irv, Sonny, and Calendar People,

Perhaps D is a hexadecimal numeric digit (still would not be 0-8 or 1-7 but perhaps 1-E. By the way, I think it is a mistake to specify both upper and lower case letters. Too much potential for an error.

Alternatively, one could encode the week by using 1-7 and also add another digit with values from 1-2 indicating which week in the fortnight is being referenced.

Victor

On Mon, Jan 30, 2012 at 6:36 AM, Irv Bromberg <irv.bromberg@...> wrote:

On 2012 Jan 26, at 11:48 , Irv Bromberg wrote:

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Irv adds:  Actually D, if numeric, has to have two digits because a fortnight has 14 days.  A single digit could be used for the leap week, but that is not a reliable way to distinguish the leap week because people might omit the leading zero of D for the first week of fortnights.

[Irv Bromberg]

Irv replies:

I agree that letter case is too likely to be mistaken.

Victor's alternative format has the advantage that it never has a leading zero, and will be consistently 2 digits.

Now it occurs to me that the leap week could be designated week 3 of a fortnight, so it will have the same fortnight letter.

-- Irv

On 2012 Jan 30, at 10:46 , Victor Engel wrote:

Perhaps D is a hexadecimal numeric digit (still would not be 0-8 or 1-7 but perhaps 1-E. By the way, I think it is a mistake to specify both upper and lower case letters. Too much potential for an error.

Alternatively, one could encode the week by using 1-7 and also add another digit with values from 1-2 indicating which week in the fortnight is being referenced.

Victor

On Mon, Jan 30, 2012 at 6:36 AM, Irv Bromberg <irv.bromberg@...> wrote:

On 2012 Jan 26, at 11:48 , Irv Bromberg wrote:

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Irv adds:  Actually D, if numeric, has to have two digits because a fortnight has 14 days.  A single digit could be used for the leap week, but that is not a reliable way to distinguish the leap week because people might omit the leading zero of D for the first week of fortnights.

[Brillig]

Sonny,

I think you're the only one who believe is it would be a good idea to have weekdays varying from 1-7, 1-8, and 1-9.

Victor
2012C11

On Mon, Jan 30, 2012 at 11:55 AM, Sonny Pondrom <sonny@...> wrote:

It is a good idea to keep the week days 1-7 during the year and 1-8 for week 52 (1-9 on leap years).   But then the Fortnight format must represent week 1 and 2.   One way to do this is with two letters (FF).  This second character could be a 1/2, a/b, or any other characters that represent something with two sides or half's.     

Sonny Pondrom

sonny@...

2012Xb7 = 2012-1-30 

"YYYYFFD"

 

On Jan 30, 2012, at 9:46 AM, Victor Engel wrote:

Dear Irv, Sonny, and Calendar People,

Perhaps D is a hexadecimal numeric digit (still would not be 0-8 or 1-7 but perhaps 1-E. By the way, I think it is a mistake to specify both upper and lower case letters. Too much potential for an error.

Alternatively, one could encode the week by using 1-7 and also add another digit with values from 1-2 indicating which week in the fortnight is being referenced.

Victor

On Mon, Jan 30, 2012 at 6:36 AM, Irv Bromberg <irv.bromberg@...> wrote:

On 2012 Jan 26, at 11:48 , Irv Bromberg wrote:

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Irv adds:  Actually D, if numeric, has to have two digits because a fortnight has 14 days.  A single digit could be used for the leap week, but that is not a reliable way to distinguish the leap week because people might omit the leading zero of D for the first week of fortnights.

[Brillig]

We must be discussing different things. I thought the subject was a fortnight calendar having a leap week. The most straightforward way to do that would be to use the ISO weekday calendar. The year number would be the Gregorian year number that corresponds to almost all days in the year. The first day of the first fortnight would be the first day of the first week in the ISO weekday calendar. Each fortnight has two weeks, designated 1 and 2. Days of the week are designated 1 through 7. On years with a leap week, The leap week can be joined with the previous weeks to form a three week fortnight.

Thus today is 2012C11 since we're in year 2012 and in day 1 of week 1 of fortnight C. Here is the current year, with spaces inserted between fortnights (first date is Gregorian -- second is the fortnight calendar just described):

2012-01-02 2012A11
2012-01-03 2012A12
2012-01-04 2012A13
2012-01-05 2012A14
2012-01-06 2012A15
2012-01-07 2012A16
2012-01-08 2012A17
2012-01-09 2012A21
2012-01-10 2012A22
2012-01-11 2012A23
2012-01-12 2012A24
2012-01-13 2012A25
2012-01-14 2012A26
2012-01-15 2012A27

2012-01-16 2012B11
2012-01-17 2012B12
2012-01-18 2012B13
2012-01-19 2012B14
2012-01-20 2012B15
2012-01-21 2012B16
2012-01-22 2012B17
2012-01-23 2012B21
2012-01-24 2012B22
2012-01-25 2012B23
2012-01-26 2012B24
2012-01-27 2012B25
2012-01-28 2012B26
2012-01-29 2012B27

2012-01-30 2012C11
2012-01-31 2012C12
2012-02-01 2012C13
2012-02-02 2012C14
2012-02-03 2012C15
2012-02-04 2012C16
2012-02-05 2012C17
2012-02-06 2012C21
2012-02-07 2012C22
2012-02-08 2012C23
2012-02-09 2012C24
2012-02-10 2012C25
2012-02-11 2012C26
2012-02-12 2012C27

2012-02-13 2012D11
2012-02-14 2012D12
2012-02-15 2012D13
2012-02-16 2012D14
2012-02-17 2012D15
2012-02-18 2012D16
2012-02-19 2012D17
2012-02-20 2012D21
2012-02-21 2012D22
2012-02-22 2012D23
2012-02-23 2012D24
2012-02-24 2012D25
2012-02-25 2012D26
2012-02-26 2012D27

2012-02-27 2012E11
2012-02-28 2012E12
2012-02-29 2012E13
2012-03-01 2012E14
2012-03-02 2012E15
2012-03-03 2012E16
2012-03-04 2012E17
2012-03-05 2012E21
2012-03-06 2012E22
2012-03-07 2012E23
2012-03-08 2012E24
2012-03-09 2012E25
2012-03-10 2012E26
2012-03-11 2012E27

2012-03-12 2012F11
2012-03-13 2012F12
2012-03-14 2012F13
2012-03-15 2012F14
2012-03-16 2012F15
2012-03-17 2012F16
2012-03-18 2012F17
2012-03-19 2012F21
2012-03-20 2012F22
2012-03-21 2012F23
2012-03-22 2012F24
2012-03-23 2012F25
2012-03-24 2012F26
2012-03-25 2012F27

2012-03-26 2012G11
2012-03-27 2012G12
2012-03-28 2012G13
2012-03-29 2012G14
2012-03-30 2012G15
2012-03-31 2012G16
2012-04-01 2012G17
2012-04-02 2012G21
2012-04-03 2012G22
2012-04-04 2012G23
2012-04-05 2012G24
2012-04-06 2012G25
2012-04-07 2012G26
2012-04-08 2012G27

2012-04-09 2012H11
2012-04-10 2012H12
2012-04-11 2012H13
2012-04-12 2012H14
2012-04-13 2012H15
2012-04-14 2012H16
2012-04-15 2012H17
2012-04-16 2012H21
2012-04-17 2012H22
2012-04-18 2012H23
2012-04-19 2012H24
2012-04-20 2012H25
2012-04-21 2012H26
2012-04-22 2012H27

2012-04-23 2012I11
2012-04-24 2012I12
2012-04-25 2012I13
2012-04-26 2012I14
2012-04-27 2012I15
2012-04-28 2012I16
2012-04-29 2012I17
2012-04-30 2012I21
2012-05-01 2012I22
2012-05-02 2012I23
2012-05-03 2012I24
2012-05-04 2012I25
2012-05-05 2012I26
2012-05-06 2012I27

2012-05-07 2012J11
2012-05-08 2012J12
2012-05-09 2012J13
2012-05-10 2012J14
2012-05-11 2012J15
2012-05-12 2012J16
2012-05-13 2012J17
2012-05-14 2012J21
2012-05-15 2012J22
2012-05-16 2012J23
2012-05-17 2012J24
2012-05-18 2012J25
2012-05-19 2012J26
2012-05-20 2012J27

2012-05-21 2012K11
2012-05-22 2012K12
2012-05-23 2012K13
2012-05-24 2012K14
2012-05-25 2012K15
2012-05-26 2012K16
2012-05-27 2012K17
2012-05-28 2012K21
2012-05-29 2012K22
2012-05-30 2012K23
2012-05-31 2012K24
2012-06-01 2012K25
2012-06-02 2012K26
2012-06-03 2012K27

2012-06-04 2012L11
2012-06-05 2012L12
2012-06-06 2012L13
2012-06-07 2012L14
2012-06-08 2012L15
2012-06-09 2012L16
2012-06-10 2012L17
2012-06-11 2012L21
2012-06-12 2012L22
2012-06-13 2012L23
2012-06-14 2012L24
2012-06-15 2012L25
2012-06-16 2012L26
2012-06-17 2012L27

2012-06-18 2012M11
2012-06-19 2012M12
2012-06-20 2012M13
2012-06-21 2012M14
2012-06-22 2012M15
2012-06-23 2012M16
2012-06-24 2012M17
2012-06-25 2012M21
2012-06-26 2012M22
2012-06-27 2012M23
2012-06-28 2012M24
2012-06-29 2012M25
2012-06-30 2012M26
2012-07-01 2012M27

2012-07-02 2012N11
2012-07-03 2012N12
2012-07-04 2012N13
2012-07-05 2012N14
2012-07-06 2012N15
2012-07-07 2012N16
2012-07-08 2012N17
2012-07-09 2012N21
2012-07-10 2012N22
2012-07-11 2012N23
2012-07-12 2012N24
2012-07-13 2012N25
2012-07-14 2012N26
2012-07-15 2012N27

2012-07-16 2012O11
2012-07-17 2012O12
2012-07-18 2012O13
2012-07-19 2012O14
2012-07-20 2012O15
2012-07-21 2012O16
2012-07-22 2012O17
2012-07-23 2012O21
2012-07-24 2012O22
2012-07-25 2012O23
2012-07-26 2012O24
2012-07-27 2012O25
2012-07-28 2012O26
2012-07-29 2012O27

2012-07-30 2012P11
2012-07-31 2012P12
2012-08-01 2012P13
2012-08-02 2012P14
2012-08-03 2012P15
2012-08-04 2012P16
2012-08-05 2012P17
2012-08-06 2012P21
2012-08-07 2012P22
2012-08-08 2012P23
2012-08-09 2012P24
2012-08-10 2012P25
2012-08-11 2012P26
2012-08-12 2012P27

2012-08-13 2012Q11
2012-08-14 2012Q12
2012-08-15 2012Q13
2012-08-16 2012Q14
2012-08-17 2012Q15
2012-08-18 2012Q16
2012-08-19 2012Q17
2012-08-20 2012Q21
2012-08-21 2012Q22
2012-08-22 2012Q23
2012-08-23 2012Q24
2012-08-24 2012Q25
2012-08-25 2012Q26
2012-08-26 2012Q27

2012-08-27 2012R11
2012-08-28 2012R12
2012-08-29 2012R13
2012-08-30 2012R14
2012-08-31 2012R15
2012-09-01 2012R16
2012-09-02 2012R17
2012-09-03 2012R21
2012-09-04 2012R22
2012-09-05 2012R23
2012-09-06 2012R24
2012-09-07 2012R25
2012-09-08 2012R26
2012-09-09 2012R27

2012-09-10 2012S11
2012-09-11 2012S12
2012-09-12 2012S13
2012-09-13 2012S14
2012-09-14 2012S15
2012-09-15 2012S16
2012-09-16 2012S17
2012-09-17 2012S21
2012-09-18 2012S22
2012-09-19 2012S23
2012-09-20 2012S24
2012-09-21 2012S25
2012-09-22 2012S26
2012-09-23 2012S27

2012-09-24 2012T11
2012-09-25 2012T12
2012-09-26 2012T13
2012-09-27 2012T14
2012-09-28 2012T15
2012-09-29 2012T16
2012-09-30 2012T17
2012-10-01 2012T21
2012-10-02 2012T22
2012-10-03 2012T23
2012-10-04 2012T24
2012-10-05 2012T25
2012-10-06 2012T26
2012-10-07 2012T27

2012-10-08 2012U11
2012-10-09 2012U12
2012-10-10 2012U13
2012-10-11 2012U14
2012-10-12 2012U15
2012-10-13 2012U16
2012-10-14 2012U17
2012-10-15 2012U21
2012-10-16 2012U22
2012-10-17 2012U23
2012-10-18 2012U24
2012-10-19 2012U25
2012-10-20 2012U26
2012-10-21 2012U27

2012-10-22 2012V11
2012-10-23 2012V12
2012-10-24 2012V13
2012-10-25 2012V14
2012-10-26 2012V15
2012-10-27 2012V16
2012-10-28 2012V17
2012-10-29 2012V21
2012-10-30 2012V22
2012-10-31 2012V23
2012-11-01 2012V24
2012-11-02 2012V25
2012-11-03 2012V26
2012-11-04 2012V27

2012-11-05 2012W11
2012-11-06 2012W12
2012-11-07 2012W13
2012-11-08 2012W14
2012-11-09 2012W15
2012-11-10 2012W16
2012-11-11 2012W17
2012-11-12 2012W21
2012-11-13 2012W22
2012-11-14 2012W23
2012-11-15 2012W24
2012-11-16 2012W25
2012-11-17 2012W26
2012-11-18 2012W27

2012-11-19 2012X11
2012-11-20 2012X12
2012-11-21 2012X13
2012-11-22 2012X14
2012-11-23 2012X15
2012-11-24 2012X16
2012-11-25 2012X17
2012-11-26 2012X21
2012-11-27 2012X22
2012-11-28 2012X23
2012-11-29 2012X24
2012-11-30 2012X25
2012-12-01 2012X26
2012-12-02 2012X27

2012-12-03 2012Y11
2012-12-04 2012Y12
2012-12-05 2012Y13
2012-12-06 2012Y14
2012-12-07 2012Y15
2012-12-08 2012Y16
2012-12-09 2012Y17
2012-12-10 2012Y21
2012-12-11 2012Y22
2012-12-12 2012Y23
2012-12-13 2012Y24
2012-12-14 2012Y25
2012-12-15 2012Y26
2012-12-16 2012Y27

2012-12-17 2012Z11
2012-12-18 2012Z12
2012-12-19 2012Z13
2012-12-20 2012Z14
2012-12-21 2012Z15
2012-12-22 2012Z16
2012-12-23 2012Z17
2012-12-24 2012Z21
2012-12-25 2012Z22
2012-12-26 2012Z23
2012-12-27 2012Z24
2012-12-28 2012Z25
2012-12-29 2012Z26
2012-12-30 2012Z27

The next leap week is in 2015:

2015-12-14 2015Z11
2015-12-15 2015Z12
2015-12-16 2015Z13
2015-12-17 2015Z14
2015-12-18 2015Z15
2015-12-19 2015Z16
2015-12-20 2015Z17
2015-12-21 2015Z21
2015-12-22 2015Z22
2015-12-23 2015Z23
2015-12-24 2015Z24
2015-12-25 2015Z25
2015-12-26 2015Z26
2015-12-27 2015Z27
2015-12-28 2015Z31
2015-12-29 2015Z32
2015-12-30 2015Z33
2015-12-31 2015Z34
2016-01-01 2015Z35
2016-01-02 2015Z36
2016-01-03 2015Z37

On Mon, Jan 30, 2012 at 4:57 PM, Sonny Pondrom <sonny@...> wrote:

Dear Irv, Victor and Calendar People,

Thank you for bring up these concerns (I found some errors too).  The revision below shows this year's Perpetual Fortnight calendar, Day 1 starts on a Tuesday.  Using the FFD format, the first week could be written many ways, but Aa1 to Aa7 has a starting look.   The sub-table at the bottom shows the weekday numbers 1 to 9.  The last two days could then be named Zb8 & Zb9, Zc1 and Zc2,  or Zc_ & Zd_.    Note that if these days were blank days, the starting weekday would be fixed.  

Sonny Pondrom

sonny@...

2012Xb7 

"YYYYFFD"

 

On Jan 30, 2012, at 10:00 AM, Irv Bromberg wrote:

Irv replies:

I agree that letter case is too likely to be mistaken.

Victor's alternative format has the advantage that it never has a leading zero, and will be consistently 2 digits.

Now it occurs to me that the leap week could be designated week 3 of a fortnight, so it will have the same fortnight letter.

-- Irv

On 2012 Jan 30, at 10:46 , Victor Engel wrote:

Perhaps D is a hexadecimal numeric digit (still would not be 0-8 or 1-7 but perhaps 1-E. By the way, I think it is a mistake to specify both upper and lower case letters. Too much potential for an error.

Alternatively, one could encode the week by using 1-7 and also add another digit with values from 1-2 indicating which week in the fortnight is being referenced.

Victor

On Mon, Jan 30, 2012 at 6:36 AM, Irv Bromberg <irv.bromberg@...> wrote:

On 2012 Jan 26, at 11:48 , Irv Bromberg wrote:

Sonny suggested the date format YYYY/FN/D where FN=01 to 26, D=0-8.

the date format could be YYYYFD where F is a capital letter A-Z for normal fortnights or a-z for the leap week, and D is a digit 1-7.

Irv adds:  Actually D, if numeric, has to have two digits because a fortnight has 14 days.  A single digit could be used for the leap week, but that is not a reliable way to distinguish the leap week because people might omit the leading zero of D for the first week of fortnights.

[Brillig]

Sonny,

I don't know what it is about your messages, but I find them hard to follow, formattingwise. Perhaps you are posting through nabble or something. In any case, if I leave something out of context, it's probably because I've missed it because I simply don't see it from the way your posts are formatted.

On Mon, Jan 30, 2012 at 8:52 PM, Sonny Pondrom <sonny@...> wrote:

Dear Victor,

Thanks for the examples.  See comments below:

Sonny Pondromsonny@...2012Xb7 "YYYYFFD" 

On Jan 30, 2012, at 5:16 PM, Victor Engel wrote:

We must be discussing different things. I thought the subject was a fortnight calendar having a leap week. 

We are discussing two different solutions to the same problem.  

I wonder. What do you think the problem is?

The most straightforward way to do that would be to use the ISO weekday calendar. The year number would be the Gregorian year number that corresponds to almost all days in the year. 

I'm inclined to desire a calendar with every day of the year.

What does that even mean? Doesn't every calendar with a year have every day of the year? Seems almost tautological.
 

  My solution matches the ISO calendar day for day every year.  

Which ISO calendar?
 

If a group can use the current calendar, they should be able to use this proposed calendar.  See Facebook for a 2011 Fortnight version where Day 1 is Tue, 2 is Wed, etc.

Can't you post it here as plain text? I'm not ready to integrate facebook into my email life. In any case, why choose Tuesday as day 1? That seems odd.

 

The first day of the first fortnight would be the first day of the first week in the ISO weekday calendar. 

This is desirable, but not at the cost of placing the Leap year day anywhere between New Year's Day and New Year's Eve. 

There is no leap year day in a leap week calendar. Also what other days are there besides those between New Year's Day and New Year's Eve? That would seem to be the entire year.

Each fortnight has two weeks, designated 1 and 2. Days of the week are designated 1 through 7. On years with a leap week, The leap week can be joined with the previous weeks to form a three week fortnight.

Thus today is 2012C11 since we're in year 2012 and in day 1 of week 1 of fortnight C. 

Using 11 together is not as clear as using weeks a and b.  Your example would be: 2012Ca1.

Of course, it is. Now you've mixed case, which can be problematic. For one, in speech, having to say the case of a letter is cumbersome. Secondly, when anticipating algorithms and computer programs, having case sensitive data can be problematic. I give you an example from my own experience. My in-laws have email addresses that are case sensitive. That is a problem because many programs out there assume, incorrectly, that email addresses are case insensitive. Domain names are case insensitive, but email address need not be. In this case, two numeric digits is much better than two digits with different case. OK, disregard the case, then. I have no problem with that. Six of one, half a dozen of the other. A, B, and C work just as well as 1, 2, and 3 (although, I must say I prefer the latter).

Here is the current year, with spaces inserted between fortnights (first date is Gregorian -- second is the fortnight calendar just described):

The two numbers at the end look like a monthly calendar.  The a and b make the 1 and 7 standout better.

No they don't They stand out exactly the same. And so what if the numeric version doesn't make the last digit stand out better? We're talking about a fortnight calendar, so the last two should be considered together. They work better as a base 7 number to me.

 
2012-01-02 2012A11 2011Aa1
2012-01-03 2012A12 2011Aa2
2012-01-04 2012A13 2011Aa3
2012-01-05 2012A14 2011Aa4
2012-01-06 2012A15 2011Aa5
2012-01-07 2012A16 2011Aa6
2012-01-08 2012A17 2011Aa7
2012-01-09 2012A21 2011Ab1
2012-01-10 2012A22 2011Ab2
2012-01-11 2012A23 2011Ab3
2012-01-12 2012A24 2011Ab4
2012-01-13 2012A25 2011Ab5
2012-01-14 2012A26 2011Ab6
2012-01-15 2012A27 2011Ab7

2012-02-27 2012E11
2012-02-28 2012E12
2012-02-29 2012E13 - This day will change next 5 or 6 years

Don't you want to drop this?  

Please explain what you mean here. I have no idea what you're talking about. There is no situation where the successor of XXXXE12 is not XXXXE13, where XXXX is the year number. If you're complaining about 2012-02-29, I don't care about that because it's part of a different calendar. I included that column just as a reference. The new calendar need not know such details about the old calendar.
 

2012-03-01 2012E14
2012-03-02 2012E15
2012-03-03 2012E16
2012-03-04 2012E17
2012-03-05 2012E21
2012-03-06 2012E22
2012-03-07 2012E23
2012-03-08 2012E24
2012-03-09 2012E25
2012-03-10 2012E26
2012-03-11 2012E27

Skipping B thru Z

Postponing December 31, 2012

Postponing December 31, 2013

Postponing December 31, 2014

Postponing December 31, 2015

????
 

The next leap week is in 2015:  This is the most confusing part.  If this could be a simple as 4 years, 100 years and 400 year rule, then the following would be OK.  

What's confusing? I'm simply following the ISO leap week rule. I won't go into how that works, since it's well documented elsewhere. Anyway, the point of following the ISO leap week rule is that it is already a standard. Some other leap week rule could be followed. But that wasn't the point of my post. The point of my post was to illustrate my proposed notation using a calendar that people already know about.

2015-12-14 2015Z11 2015Za1
2015-12-15 2015Z12 2015Za2
2015-12-16 2015Z13 2015Za3
2015-12-17 2015Z14 2015Za4
2015-12-18 2015Z15 2015Za5
2015-12-19 2015Z16 2015Za6
2015-12-20 2015Z17 2015Za7
2015-12-21 2015Z21 2015Zb1
2015-12-22 2015Z22 2015Zb2
2015-12-23 2015Z23 2015Zb3
2015-12-24 2015Z24 2015Zb4
2015-12-25 2015Z25 2015Zb5
2015-12-26 2015Z26 2015Zb6
2015-12-27 2015Z27 2015Zb7
2015-12-28 2015Z31 2015Zc1
2015-12-29 2015Z32 2015Zc2
2015-12-30 2015Z33 2015Zc3
2015-12-31 2015Z34 2015Zc4
2016-01-01 2015Z35 2015Zc5
2016-01-02 2015Z36 2015Zc6
2016-01-03 2015Z37 2015Zc7

Having so many days in another year is not desirable. 

IT IS A LEAP WEEK CALENDAR! THAT'S WHAT YOU GET WHEN YOU HAVE A LEAP WEEK CALENDAR.

Besides, those days are not in a different year. They're in the same year: 2015. Please ignore the year specified in the left column. That is a reference only. One could say that the year number portion of the leap week date is a mismatch for the year numbers in the Gregorian calendar, BUT THAT'S A CONSEQUENCE OF THE ISO LEAP WEEK RULES.

It's apparent, that you are proposing a calendar that is NOT a leap week calendar. Consequently, we are NOT attempting to solve the same problem. My problem is specifically to specify a notation that is to be used with a fortnight calendar having a leapweek as suggested earlier (by Karl, I think).

Victor