version 1998-08-15 rose

ROZE

ROZE is the Reformed Old-fashioned Zodiacal Ephemeral calendar.

Overview
Conversion Table Gregorian / ROZE
Additional Materials


Overview

Like the old Maya had their solar and Venus years (haab and tzolkin), people in the western world also have a kind of dual time system (Gregorian and zodiacal). But the zodiacal system goes mostly unnoticed, although nearly everyone knows the personal zodiac sign. While the Gregorian system runs linear and counts years, the zodiacal calendar is essentially cyclical and years are commonly not counted.

The ROZE year has twelve months of different lengths, mostly 30 and 31 days. Months approximate the traditional zodiacal signs and are named after them. Basically, this is a Gregorian calendar with the same leap rules - the only differences are the month scheme and the beginning of the year at vernal equinox.

This calendar is reformed, because it tries to avoid months of length 28, 29, and 32 as in some of the old zodiac systems (It does not succeed fully, however, because of the unequal lengths of the astronomical seasons - see below).

For simplicity, it was deemed necessary to keep the solstices and equinoxes fixed, although they shift a day or so in astronomical reality (see below). Therefore, it is old-fashioned; especially because it tries to keep the zodiacal signs where they traditionally have been in popular western horoscopes.

It is ephemeral, for it will probably be used only for a very short time (if at all) until it is replaced by something with a better fit (and because I needed an "E" ;-)

The zodiac signs according to Webster's Ninth New Collegiate Dictionary and Webster's Collegiate Thesaurus, First Digital Edition, Version 3.0, NeXT Computer, Inc., and Merriam-Webster Inc., Copyright 1988, 1992:

sign          time interval    days

 Aries       (03-21 - 04-19)   30
 Taurus      (04-20 - 05-20)   31
 Gemini      (05-21 - 06-21)   32
SS : Summer Solstice: 06-21    93 

 Cancer      (06-22 - 07-22)   31
 Leo         (07-23 - 08-22)   31
 Virgo       (08-23 - 09-22)   31
AE : Autumn Equinox:  09-22    93

 Libra       (09-23 - 10-23)   31
 Scorpio     (10-24 - 11-21)   29
 Sagittarius (11-22 - 12-21)   30
WS : Winter Solstice: 12-21    90

 Capricorn   (12-22 - 01-19)   29
 Aquarius    (01-20 - 02-18)   30
 Pisces      (02-19 - 03-20)   30(31)
VE : Vernal Equinox:  03-20    89


month lengths:               number of months with this length
32|    *|     |     |        1
31|  *  |* * *|*    |    L   5 (6)
30|*    |     |    *|  * *   4 (3)
29|     |     |  *  |*       2
  |A T G|C L V|L S S|C A P
  V     S     A     W
  E     S     E     S
Summer months are generally longer than winter months. L denotes the leap year.
Solstice and equinox data are approximated from Earth's Seasons 1992-2005.Vernal (= spring) Equinox is on the 20th in about 75% of the cases and on the 21st in about 25% of the cases (effect of the Gregorian leap year rules), so the 20th is chosen here.
Since Autumn Equinox is on either September 22nd or 23rd (each with a relative frequency of about 50 %), and Winter Solstice is on December 21st or 22nd (each about 50 % of the time), we are free to choose the date for our fix.

Fixes are common in calendars, since reality can only be approximated (see note on precision). This fix is a conscious choice to accept an error in the order of a day or so.


Conversion Table Gregorian / ROZE

Normally ROZE starts on Aries 1 and ends on Pisces 30. In Gregorian leap years, there is a day Pisces 31; the Gregorian days shift accordingly.

The following table has been computed for a normal year of 365 days. It gives (in order) the Gregorian date in month-day format, the day number in the Gregorian year, the day number in the zodiacal year, the ROZE date.

Gregorian   ROZE
03-21   80    1  Aries-01
03-22   81    2  Aries-02
03-23   82    3  Aries-03
03-24   83    4  Aries-04
03-25   84    5  Aries-05
03-26   85    6  Aries-06
03-27   86    7  Aries-07
03-28   87    8  Aries-08
03-29   88    9  Aries-09
03-30   89   10  Aries-10
03-31   90   11  Aries-11
04-01   91   12  Aries-12
04-02   92   13  Aries-13
04-03   93   14  Aries-14
04-04   94   15  Aries-15
04-05   95   16  Aries-16
04-06   96   17  Aries-17
04-07   97   18  Aries-18
04-08   98   19  Aries-19
04-09   99   20  Aries-20
04-10  100   21  Aries-21
04-11  101   22  Aries-22
04-12  102   23  Aries-23
04-13  103   24  Aries-24
04-14  104   25  Aries-25
04-15  105   26  Aries-26
04-16  106   27  Aries-27
04-17  107   28  Aries-28
04-18  108   29  Aries-29
04-19  109   30  Aries-30
04-20  110   31  Taurus-01
04-21  111   32  Taurus-02
04-22  112   33  Taurus-03
04-23  113   34  Taurus-04
04-24  114   35  Taurus-05
04-25  115   36  Taurus-06
04-26  116   37  Taurus-07
04-27  117   38  Taurus-08
04-28  118   39  Taurus-09
04-29  119   40  Taurus-10
04-30  120   41  Taurus-11
05-01  121   42  Taurus-12
05-02  122   43  Taurus-13
05-03  123   44  Taurus-14
05-04  124   45  Taurus-15
05-05  125   46  Taurus-16
05-06  126   47  Taurus-17
05-07  127   48  Taurus-18
05-08  128   49  Taurus-19
05-09  129   50  Taurus-20
05-10  130   51  Taurus-21
05-11  131   52  Taurus-22
05-12  132   53  Taurus-23
05-13  133   54  Taurus-24
05-14  134   55  Taurus-25
05-15  135   56  Taurus-26
05-16  136   57  Taurus-27
05-17  137   58  Taurus-28
05-18  138   59  Taurus-29
05-19  139   60  Taurus-30
05-20  140   61  Taurus-31
05-21  141   62  Gemini-01
05-22  142   63  Gemini-02
05-23  143   64  Gemini-03
05-24  144   65  Gemini-04
05-25  145   66  Gemini-05
05-26  146   67  Gemini-06
05-27  147   68  Gemini-07
05-28  148   69  Gemini-08
05-29  149   70  Gemini-09
05-30  150   71  Gemini-10
05-31  151   72  Gemini-11
06-01  152   73  Gemini-12
06-02  153   74  Gemini-13
06-03  154   75  Gemini-14
06-04  155   76  Gemini-15
06-05  156   77  Gemini-16
06-06  157   78  Gemini-17
06-07  158   79  Gemini-18
06-08  159   80  Gemini-19
06-09  160   81  Gemini-20
06-10  161   82  Gemini-21
06-11  162   83  Gemini-22
06-12  163   84  Gemini-23
06-13  164   85  Gemini-24
06-14  165   86  Gemini-25
06-15  166   87  Gemini-26
06-16  167   88  Gemini-27
06-17  168   89  Gemini-28
06-18  169   90  Gemini-29
06-19  170   91  Gemini-30
06-20  171   92  Gemini-31
06-21  172   93  Gemini-32
06-22  173   94  Cancer-01
06-23  174   95  Cancer-02
06-24  175   96  Cancer-03
06-25  176   97  Cancer-04
06-26  177   98  Cancer-05
06-27  178   99  Cancer-06
06-28  179  100  Cancer-07
06-29  180  101  Cancer-08
06-30  181  102  Cancer-09
07-01  182  103  Cancer-10
07-02  183  104  Cancer-11
07-03  184  105  Cancer-12
07-04  185  106  Cancer-13
07-05  186  107  Cancer-14
07-06  187  108  Cancer-15
07-07  188  109  Cancer-16
07-08  189  110  Cancer-17
07-09  190  111  Cancer-18
07-10  191  112  Cancer-19
07-11  192  113  Cancer-20
07-12  193  114  Cancer-21
07-13  194  115  Cancer-22
07-14  195  116  Cancer-23
07-15  196  117  Cancer-24
07-16  197  118  Cancer-25
07-17  198  119  Cancer-26
07-18  199  120  Cancer-27
07-19  200  121  Cancer-28
07-20  201  122  Cancer-29
07-21  202  123  Cancer-30
07-22  203  124  Cancer-31
07-23  204  125  Leo-01
07-24  205  126  Leo-02
07-25  206  127  Leo-03
07-26  207  128  Leo-04
07-27  208  129  Leo-05
07-28  209  130  Leo-06
07-29  210  131  Leo-07
07-30  211  132  Leo-08
07-31  212  133  Leo-09
08-01  213  134  Leo-10
08-02  214  135  Leo-11
08-03  215  136  Leo-12
08-04  216  137  Leo-13
08-05  217  138  Leo-14
08-06  218  139  Leo-15
08-07  219  140  Leo-16
08-08  220  141  Leo-17
08-09  221  142  Leo-18
08-10  222  143  Leo-19
08-11  223  144  Leo-20
08-12  224  145  Leo-21
08-13  225  146  Leo-22
08-14  226  147  Leo-23
08-15  227  148  Leo-24
08-16  228  149  Leo-25
08-17  229  150  Leo-26
08-18  230  151  Leo-27
08-19  231  152  Leo-28
08-20  232  153  Leo-29
08-21  233  154  Leo-30
08-22  234  155  Leo-31
08-23  235  156  Virgo-01
08-24  236  157  Virgo-02
08-25  237  158  Virgo-03
08-26  238  159  Virgo-04
08-27  239  160  Virgo-05
08-28  240  161  Virgo-06
08-29  241  162  Virgo-07
08-30  242  163  Virgo-08
08-31  243  164  Virgo-09
09-01  244  165  Virgo-10
09-02  245  166  Virgo-11
09-03  246  167  Virgo-12
09-04  247  168  Virgo-13
09-05  248  169  Virgo-14
09-06  249  170  Virgo-15
09-07  250  171  Virgo-16
09-08  251  172  Virgo-17
09-09  252  173  Virgo-18
09-10  253  174  Virgo-19
09-11  254  175  Virgo-20
09-12  255  176  Virgo-21
09-13  256  177  Virgo-22
09-14  257  178  Virgo-23
09-15  258  179  Virgo-24
09-16  259  180  Virgo-25
09-17  260  181  Virgo-26
09-18  261  182  Virgo-27
09-19  262  183  Virgo-28
09-20  263  184  Virgo-29
09-21  264  185  Virgo-30
09-22  265  186  Virgo-31
09-23  266  187  Libra-01
09-24  267  188  Libra-02
09-25  268  189  Libra-03
09-26  269  190  Libra-04
09-27  270  191  Libra-05
09-28  271  192  Libra-06
09-29  272  193  Libra-07
09-30  273  194  Libra-08
10-01  274  195  Libra-09
10-02  275  196  Libra-10
10-03  276  197  Libra-11
10-04  277  198  Libra-12
10-05  278  199  Libra-13
10-06  279  200  Libra-14
10-07  280  201  Libra-15
10-08  281  202  Libra-16
10-09  282  203  Libra-17
10-10  283  204  Libra-18
10-11  284  205  Libra-19
10-12  285  206  Libra-20
10-13  286  207  Libra-21
10-14  287  208  Libra-22
10-15  288  209  Libra-23
10-16  289  210  Libra-24
10-17  290  211  Libra-25
10-18  291  212  Libra-26
10-19  292  213  Libra-27
10-20  293  214  Libra-28
10-21  294  215  Libra-29
10-22  295  216  Libra-30
10-23  296  217  Libra-31
10-24  297  218  Scorpio-01
10-25  298  219  Scorpio-02
10-26  299  220  Scorpio-03
10-27  300  221  Scorpio-04
10-28  301  222  Scorpio-05
10-29  302  223  Scorpio-06
10-30  303  224  Scorpio-07
10-31  304  225  Scorpio-08
11-01  305  226  Scorpio-09
11-02  306  227  Scorpio-10
11-03  307  228  Scorpio-11
11-04  308  229  Scorpio-12
11-05  309  230  Scorpio-13
11-06  310  231  Scorpio-14
11-07  311  232  Scorpio-15
11-08  312  233  Scorpio-16
11-09  313  234  Scorpio-17
11-10  314  235  Scorpio-18
11-11  315  236  Scorpio-19
11-12  316  237  Scorpio-20
11-13  317  238  Scorpio-21
11-14  318  239  Scorpio-22
11-15  319  240  Scorpio-23
11-16  320  241  Scorpio-24
11-17  321  242  Scorpio-25
11-18  322  243  Scorpio-26
11-19  323  244  Scorpio-27
11-20  324  245  Scorpio-28
11-21  325  246  Scorpio-29
11-22  326  247  Sagittarius-01
11-23  327  248  Sagittarius-02
11-24  328  249  Sagittarius-03
11-25  329  250  Sagittarius-04
11-26  330  251  Sagittarius-05
11-27  331  252  Sagittarius-06
11-28  332  253  Sagittarius-07
11-29  333  254  Sagittarius-08
11-30  334  255  Sagittarius-09
12-01  335  256  Sagittarius-10
12-02  336  257  Sagittarius-11
12-03  337  258  Sagittarius-12
12-04  338  259  Sagittarius-13
12-05  339  260  Sagittarius-14
12-06  340  261  Sagittarius-15
12-07  341  262  Sagittarius-16
12-08  342  263  Sagittarius-17
12-09  343  264  Sagittarius-18
12-10  344  265  Sagittarius-19
12-11  345  266  Sagittarius-20
12-12  346  267  Sagittarius-21
12-13  347  268  Sagittarius-22
12-14  348  269  Sagittarius-23
12-15  349  270  Sagittarius-24
12-16  350  271  Sagittarius-25
12-17  351  272  Sagittarius-26
12-18  352  273  Sagittarius-27
12-19  353  274  Sagittarius-28
12-20  354  275  Sagittarius-29
12-21  355  276  Sagittarius-30
12-22  356  277  Capricorn-01
12-23  357  278  Capricorn-02
12-24  358  279  Capricorn-03
12-25  359  280  Capricorn-04
12-26  360  281  Capricorn-05
12-27  361  282  Capricorn-06
12-28  362  283  Capricorn-07
12-29  363  284  Capricorn-08
12-30  364  285  Capricorn-09
12-31  365  286  Capricorn-10
01-01    1  287  Capricorn-11
01-02    2  288  Capricorn-12
01-03    3  289  Capricorn-13
01-04    4  290  Capricorn-14
01-05    5  291  Capricorn-15
01-06    6  292  Capricorn-16
01-07    7  293  Capricorn-17
01-08    8  294  Capricorn-18
01-09    9  295  Capricorn-19
01-10   10  296  Capricorn-20
01-11   11  297  Capricorn-21
01-12   12  298  Capricorn-22
01-13   13  299  Capricorn-23
01-14   14  300  Capricorn-24
01-15   15  301  Capricorn-25
01-16   16  302  Capricorn-26
01-17   17  303  Capricorn-27
01-18   18  304  Capricorn-28
01-19   19  305  Capricorn-29
01-20   20  306  Aquarius-01
01-21   21  307  Aquarius-02
01-22   22  308  Aquarius-03
01-23   23  309  Aquarius-04
01-24   24  310  Aquarius-05
01-25   25  311  Aquarius-06
01-26   26  312  Aquarius-07
01-27   27  313  Aquarius-08
01-28   28  314  Aquarius-09
01-29   29  315  Aquarius-10
01-30   30  316  Aquarius-11
01-31   31  317  Aquarius-12
02-01   32  318  Aquarius-13
02-02   33  319  Aquarius-14
02-03   34  320  Aquarius-15
02-04   35  321  Aquarius-16
02-05   36  322  Aquarius-17
02-06   37  323  Aquarius-18
02-07   38  324  Aquarius-19
02-08   39  325  Aquarius-20
02-09   40  326  Aquarius-21
02-10   41  327  Aquarius-22
02-11   42  328  Aquarius-23
02-12   43  329  Aquarius-24
02-13   44  330  Aquarius-25
02-14   45  331  Aquarius-26
02-15   46  332  Aquarius-27
02-16   47  333  Aquarius-28
02-17   48  334  Aquarius-29
02-18   49  335  Aquarius-30
02-19   50  336  Pisces-01
02-20   51  337  Pisces-02
02-21   52  338  Pisces-03
02-22   53  339  Pisces-04
02-23   54  340  Pisces-05
02-24   55  341  Pisces-06
02-25   56  342  Pisces-07
02-26   57  343  Pisces-08
02-27   58  344  Pisces-09
02-28   59  345  Pisces-10
03-01   60  346  Pisces-11
03-02   61  347  Pisces-12
03-03   62  348  Pisces-13
03-04   63  349  Pisces-14
03-05   64  350  Pisces-15
03-06   65  351  Pisces-16
03-07   66  352  Pisces-17
03-08   67  353  Pisces-18
03-09   68  354  Pisces-19
03-10   69  355  Pisces-20
03-11   70  356  Pisces-21
03-12   71  357  Pisces-22
03-13   72  358  Pisces-23
03-14   73  359  Pisces-24
03-15   74  360  Pisces-25
03-16   75  361  Pisces-26
03-17   76  362  Pisces-27
03-18   77  363  Pisces-28
03-19   78  364  Pisces-29
03-20   79  365  Pisces-30


Additional Materials

Jean Meeus (in his book "Astronomical Algorithms", 1991) gives the
following data on the lengths of the "astronomical seasons"
(cited from an email of Simon Cassidy to CALNDR-L, 
Fri, 1998-08-14, 00:54:47 -0700):

          VE - SS        SS - AE        AE - WS            WS - VE
        0Aries-0Cancer 0Cancer-0Libra 0Libra-0Capricorn 0Capricorn-0Aries
AD 2000    92.76 days    93.65 days      89.84 days        88.99 days
AD 2500    92.37         93.81           90.22             88.84
AD 3000    91.97         93.92           90.61             88.74
AD 3500    91.57         93.96           91.01             88.71
AD 4000    91.17         93.93           91.40             88.73
AD 4500    90.79         93.84           91.79             88.82
AD 5000    90.44         93.70           92.15             88.96
This shows that presently the combination 93|93|90|89 is the best approximation of day lengths for the astronomical seasons.
Because of precession, this is the current arrangement 
(from The World Almanac and other sources, 
cited from email of Joseph McCollum to CALNDR-L, 
Fri, 1998-08-07, 21:32:58 CDT) as defined by the
International Astronomical Union:

constellation   time interval         days
Capricorn       Jan 19 - Feb 18 =       28
Aquarius        Feb 16 - Mar 11 =       24 (25)
Pisces          Mar 12 - Apr 18 =       38
Aries           Apr 19 - May 13 =       26
Taurus          May 14 - Jun 19 =       37
Gemini          Jun 20 - Jul 20 =       31
Cancer          Jul 21 - Aug  9 =       20
Leo             Aug 10 - Sep 15 =       37
Virgo           Sep 16 - Oct 30 =       45
Libra           Oct 31 - Nov 22 =       23
Scorpius	       Nov 23 - Nov 29 =        7
Ophiuchus       Nov 30 - Dec 17 =       18
Sagittarius     Dec 18 - Jan 18 =       32
An astronomical constellation is not an astrological sign. Note that there are 13 constellations in the astronomical zodiac (Ophiuchus is no standard western astrological sign).


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