Mechanic · time & pacing · farming simulation

Calendar

A count of game days grouped into weeks, seasons, or months, which the game's rules read.

stubAlso: in-game calendar, seasons, game date, days and seasonsUpdated 2026-10-22
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A calendar counts game days, and other rules read the date. Harvest Moon 64 has four seasons of 30 days, and its day turns over at 6:001.

  • SeasonsHarvest Moon 64 (1999). Four seasons of 30 days, each day turning over at 6:00.1
  • MonthsStar Trader (1974). Twelve 30-day months from January 1, 2070; a voyage takes whole days.2,3

See also

Mentioned in

Games

GameYearHowNote
Harvest Moon 641999Seasonsfour seasons of 30 days, each day turning over at 6:00
Star Trader1974Monthstwelve 30-day months from January 1, 2070; a voyage takes whole days
Every claim about this mechanic, by game (3)
Star Trader 1974Star Trader's calendar has twelve 30-day months in a 360-day year and starts on January 1, 2070.Publisher
A Star Trader voyage takes the straight-line distance divided by the ship's speed, R9 light-years a day (2/7 by default, 2 a week), rounded down to whole days, on a map 100 light-years square.Publisher
Harvest Moon 64 1999In the US release, updateClock adds a day to the date and the day of the week when the hour rolls over to 6:00, and going to bed sets the clock to 6:00 and adds the day itself. Day 31 becomes day 1 of the next season, and the fifth season is spring of the next year: four seasons of 30 days, with the year capped at 99.Code

References

  1. ^ abIn the US release, updateClock adds a day to the date and the day of the week when the hour rolls over to 6:00, and going to bed sets the clock to 6:00 and adds the day itself. Day 31 becomes day 1 of the next season, and the fifth season is spring of the next year: four seasons of 30 days, with the year capped at 99.Codeharvestwhisperer/hm64-decomp
    How we know
    132    if (gDayOfMonth >= 31) {
    src/game/time.c lines 115–146 at 9824b88 · upstream ↗
    223    gHour = 6;
    src/game/time.c lines 221–233 at 9824b88 · upstream ↗
    9#define WINTER 4
    src/game/time.h lines 6–9 at 9824b88 · upstream ↗

    Checked against the evidence by its author, an AI model, 2026-10-22.

    Checked by a second AI model, 2026-10-22.

    In the claim ledger

  2. ^Star Trader's calendar has twelve 30-day months in a 360-day year and starts on January 1, 2070.PublisherPCC Games, 1974
    How we know
    270 REM D1 IS THE DAY OF THIS YEAR (1<=D1<=360) 280 REM Y1 IS THIS YEAR 290 LET D1=1 300 LET Y1=2070
    p. 29, set-up module lines 270–300 · archived copy ↗
    3040 IF T[9,T1] <= 360 THEN 3070 3050 T[9,T1]=T[9,T1]-360 3060 T[10,T1]=T[10,T1]+1 3070 M=INT((T[9,T1]-1)/30)
    p. 27, lines 3040–3070 · archived copy ↗

    Checked against the evidence by its author, an AI model, 2026-10-22.

    Checked by a second AI model, 2026-10-22.

    In the claim ledger

  3. ^A Star Trader voyage takes the straight-line distance divided by the ship's speed, R9 light-years a day (2/7 by default, 2 a week), rounded down to whole days, on a map 100 light-years square.PublisherPCC Games, 1974 · People's Computer Company, Jan. 1974
    How we know
    2910 D2=SQR((S[11,S1]-S[11,I])^2+(S[12,S1]-S[12,I])^2)/R9 2920 D2=INT(D2)
    p. 27, lines 2910–2920 · archived copy ↗
    THE MAP IS 100 LIGHT-YEARS BY 100 LIGHT-YEARS.
    p. 29, line 5470 · archived copy ↗
    YOUR SHIPS CAN TRAVEL ABOUT TWO LIGHTYEARS IN A WEEK AND CAN CARRY UP TO 30 TONS OF CARGO.
    p. 4 · archived copy ↗

    Checked against the evidence by its author, an AI model, 2026-10-22.

    Checked by a second AI model, 2026-10-22.

    In the claim ledger

  4. ^The city clock advances once per 16-step cycle, and the date shown divides it by 4 for the month and by 48 for the year, so a month is 64 steps.CodeMicropolis (SimHacker/micropolis)
    How we know
    132      CityTime++;
    micropolis-activity/src/sim/s_sim.c lines 126–132 at c98f6b0 · upstream ↗
    711  int month = (CityTime / 4) % 12;
    micropolis-activity/src/sim/w_graph.c lines 710–711 at c98f6b0 · upstream ↗

    Checked against the evidence by its author, an AI model, 2026-10-21.

    Checked by a second AI model, 2026-10-21.

    In the claim ledger

Sources

Code