As much fun as I was having with the calendar I designed in Star Dates and Calendars, the system is a tad too unworkable. Yes, I can write a computer program to generate dates, but it is no fun to try to calculate those dates in Excel. (And odds are, whoever would be using this system in this world would have designed it for even simpler applications.)

## Absolute Dates

Absolute time is kept in an adapted form of Julian Days.

As the standards board was meeting in the late 19th century, This blog entry was made on 2022-03-12, which would be star date 2459651.

If you have a handy Tcl interpreter, you can calculate star dates with the clock command:

clock format [clock scan \$date] -format %J

In Excel, you can use the built in date functions. Excel uses a serial date system. Day 1 is the January 1, 1900. To convert between Sublight stardates and Excel serial dates, Subtract 2415018.5. (Julian dates are noon to noon.)

Humans are lazy, and will end up shortening that. This committee met in the late 19th century, and so the nearest rollover date in the past would be Julian Day 2400000 (Tue Nov 16, 1858). The next rollover day in the future will be 2500000 (Sun Aug 31, 2132). So it's standard practice to simply ditch the leading digits unless you are addressing dates well in the past, well into the future, or you happen to live in the years surrounding a rollover. And hope you aren't like the people in my second book who are on a ship that leaves Earth in 2490000 (2105-04-15) and won't get where they are going until 2510000 (2160-01-17).

## Human Dates

While absolute dates are great for calculators, it's not very useful to people. No attempt is made to make metric years and months line up with Gregorian calendar years or months. They are just a way to break up absolute time into useful, user-friendly chunks.

To convert a stardate into an Excel serial date: DATE=(STARDATE-2415018.5)

A day is 24 hours long. A year is 364 days. The year is broken into 13 months of 28 days each. (13 * 28 = 364)

The names of the months are based on the Zodiac:

Number Month Starts
1 Aries 1
2 Taurus 29
3 Gemini 57
4 Cancer 85
5 Leo 113
6 Virgo 141
7 Libra 169
8 Scorpio 197
9 Ophiuchus 225
10 Sagittarius 253
11 Capricorn 281
12 Aquarius 309
13 Pisces 337

int(floor(STARDATE/364))

This blog was posted in metric year: 6757

To calculate your Metric day of the year:

int(floor(STARDATE)) % 364

This blog was posted on the day of the year: 103

(int(floor(STARDATE/28)) % 13)+1

This blog was posted on the month of : 4 (Cancer)

or

int(floor(DAY_OF_YEAR/28))+1

This blog was posted on the month of : 4 (Cancer)

To calculate the day of the month:

(int(floor(STARDATE)) % 28)+1}

This blog was posted on the day of: 20

or

(DAY_OR_YEAR % 28)+1

This blog was posted on the day of: 20

The days of the week are the traditional days, and the do line up with the days of the week back on Earth.

 1 Sunday 2 Monday 3 Tuesday 4 Wednesday 5 Thursday 6 Friday 7 Saturday

To calculate your Day of the week:

(int(STARDATE+1) % 7)+1

This blog was posted on a: 7 (Saturday)

## Example dates

proc FORMAT_DATE {STARDATE} {
set YEAR 364
set MONTH 28
set MONTH_LIST {
{} Aries Taurus Gemini Cancer
Leo Virgo Libra Scorpio Ophiuchus
Sagittarius Capricorn Aquarius Pisces
}
set DAYS_OF_WEEK {{} Sunday Monday Tuesday Wednesday Thursday Friday Saturday}

set year  [expr {int(floor(\$STARDATE/\$YEAR))}]
set monthidx [expr {(int(floor(\$STARDATE/\$MONTH)) % 13)+1}]
set month    [lindex \$MONTH_LIST \$monthidx]
set dayweek [expr {(int(\$STARDATE+1) % 7)+1}]
set dayofweek [lindex \$DAYS_OF_WEEK \$dayweek]
set dom [expr {(int(floor(\$STARDATE)) % \$MONTH)+1}]
return "\$dayofweek, \$month \$dom, \$year"
}

 -1930000 9997 B.C. Saturday, Capricorn 13, -5303 Oldest settlements in Damascus 918025 Thu Jun 01, 2200 B.C.E. Thursday, Aries 18, 2522 Umm al Binni Crater formed 954550 Wed Jun 01, 2100 B.C.E. Wednesday, Virgo 3, 2622 Epic of Gilgamesh Written 347724 Sun Jan 07, 3761 B.C.E. Sunday, Cancer 21, 955 Start of the Hebrew Calendar 1721424 Sat Jan 01, 0001 C.E. Saturday, Gemini 13, 4729 Start of the Common Era (aka A.D.) 1720321 Tue Dec 25, 0004 B.C.E. Tuesday, Gemini 2, 4726 Birth of Christ (Estimated) 2101070 Sun Jun 01, 1040 C.E. Sunday, Gemini 7, 5772 Movable Type invented (China) 2400000 Tue Nov 16, 1858 C.E. Tuesday, Virgo 9, 6593 Start of current epoch 2415386 Tue Jan 01, 1901 C.E. Tuesday, Ophiuchus 23, 6635 Turn of the 20th Century 2440423 Sun Jul 20, 1969 C.E. Sunday, Virgo 28, 6704 Apollo 11 Touched down on the moon 2451911 Mon Jan 01, 2001 C.E. Monday, Aries 8, 6736 Turn of the 21st Century 2460367 Mon Feb 26, 2024 C.E. Monday, Cancer 8, 6759 Page last Cached 2500000 Sun Aug 31, 2132 C.E. Sunday, Taurus 21, 6868 Start of next epoch 2536727 Fri Mar 22, 2233 C.E. Friday, Aries 12, 6969 Birth of James T. Kirk

NOTE: All of the calculations for metric time use the full star date (2459317 VS 59317). You will get very different answers because 2400000 is not divisible by 364. Aries was chosen as the first month to line the calendar up with the zero axis of the plane of the ecliptic. Which was placed there because Aries also happens to be the sign of the Vernal equinox, which is where certain traditions in the Mediterranean/Near East started the astronomical/astrological year.

## Calendar

Because every month is the same length, and every day of the year happens on the same day of the week, generating a calendar is very, very easy:

 Aries Mo Tu We Th Fr Sa Su 11 22 33 44 55 66 77 88 99 1010 1111 1212 1313 1414 1515 1616 1717 1818 1919 2020 2121 2222 2323 2424 2525 2626 2727 2828
 Taurus Mo Tu We Th Fr Sa Su 129 230 331 432 533 634 735 836 937 1038 1139 1240 1341 1442 1543 1644 1745 1846 1947 2048 2149 2250 2351 2452 2553 2654 2755 2856
 Gemini Mo Tu We Th Fr Sa Su 157 258 359 460 561 662 763 864 965 1066 1167 1268 1369 1470 1571 1672 1773 1874 1975 2076 2177 2278 2379 2480 2581 2682 2783 2884
 Cancer Mo Tu We Th Fr Sa Su 185 286 387 488 589 690 791 892 993 1094 1195 1296 1397 1498 1599 16100 17101 18102 19103 20104 21105 22106 23107 24108 25109 26110 27111 28112
 Leo Mo Tu We Th Fr Sa Su 1113 2114 3115 4116 5117 6118 7119 8120 9121 10122 11123 12124 13125 14126 15127 16128 17129 18130 19131 20132 21133 22134 23135 24136 25137 26138 27139 28140
 Virgo Mo Tu We Th Fr Sa Su 1141 2142 3143 4144 5145 6146 7147 8148 9149 10150 11151 12152 13153 14154 15155 16156 17157 18158 19159 20160 21161 22162 23163 24164 25165 26166 27167 28168
 Libra Mo Tu We Th Fr Sa Su 1169 2170 3171 4172 5173 6174 7175 8176 9177 10178 11179 12180 13181 14182 15183 16184 17185 18186 19187 20188 21189 22190 23191 24192 25193 26194 27195 28196
 Scorpio Mo Tu We Th Fr Sa Su 1197 2198 3199 4200 5201 6202 7203 8204 9205 10206 11207 12208 13209 14210 15211 16212 17213 18214 19215 20216 21217 22218 23219 24220 25221 26222 27223 28224
 Ophiuchus Mo Tu We Th Fr Sa Su 1225 2226 3227 4228 5229 6230 7231 8232 9233 10234 11235 12236 13237 14238 15239 16240 17241 18242 19243 20244 21245 22246 23247 24248 25249 26250 27251 28252
 Sagittarius Mo Tu We Th Fr Sa Su 1253 2254 3255 4256 5257 6258 7259 8260 9261 10262 11263 12264 13265 14266 15267 16268 17269 18270 19271 20272 21273 22274 23275 24276 25277 26278 27279 28280
 Capricorn Mo Tu We Th Fr Sa Su 1281 2282 3283 4284 5285 6286 7287 8288 9289 10290 11291 12292 13293 14294 15295 16296 17297 18298 19299 20300 21301 22302 23303 24304 25305 26306 27307 28308
 Aquarius Mo Tu We Th Fr Sa Su 1309 2310 3311 4312 5313 6314 7315 8316 9317 10318 11319 12320 13321 14322 15323 16324 17325 18326 19327 20328 21329 22330 23331 24332 25333 26334 27335 28336
 Pisces Mo Tu We Th Fr Sa Su 1337 2338 3339 4340 5341 6342 7343 8344 9345 10346 11347 12348 13349 14350 15351 16352 17353 18354 19355 20356 21357 22358 23359 24360 25361 26362 27363 28364