---
title: "Perpetual Calendar"
type: "article"
slug: "perpetual-calendar-2"
url: "http://localhost/article/perpetual-calendar-2/"
markdown_url: "http://localhost/article/perpetual-calendar-2.md"
published_at: "2022-10-07T12:28:11+00:00"
modified_at: "2024-06-11T13:57:09+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
category:
  - name: "The RAMTOP"
    slug: "the-ramtop"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/the-ramtop/"
post_tag:
  - name: "Downloadable"
    slug: "downloadable"
    taxonomy: "post_tag"
    url: "http://localhost/tag/downloadable/"
  - name: "TS 2068"
    slug: "ts2068"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts2068/"
  - name: "Type-in program"
    slug: "type-in-program"
    taxonomy: "post_tag"
    url: "http://localhost/tag/type-in-program/"
model:
  - name: "Timex/Sinclair 2068"
    slug: "ts-2068"
    taxonomy: "model"
    url: "http://localhost/model/ts-2068/"
indiv:
  - name: "Imre Auersbacher"
    slug: "imre-auersbacher"
    taxonomy: "indiv"
    url: "http://localhost/indiv/imre-auersbacher/"
publication_r:
  id: 39272
  title: "The RAMTOP"
  type: "periodical"
  url: "http://localhost/periodical/the-ramtop/"
authors: "Imre Auersbacher"
issues_articles:
  - id: 39860
    title: "The RAMTOP Aug 1986"
    type: "issue"
    url: "http://localhost/issue/the-ramtop-aug-1986/"
pages: "4"
pubdate: "August 1986"
archive_link: false
article_media:
  - id: 55039
    title: "Perpetual Calendar 2068"
    type: "computer_media"
    url: "http://localhost/computer_media/perpetual-calendar-2068/"
---

# Perpetual Calendar

## Source Code: Perpetual Calendar 2068

```
    2 REM Perpetual Calendar 2068
    4 REM  \* 1984 I. Auersbacher 
    8 BORDER 5: DIM M$(12,9)
   10 CLS : PRINT PAPER 6;"*** CALENDAR (1583-9999 AD) *** "
   15 LET Z$=" 1 2 3 4 5 6 7 8 910111213141516171819202122232425262728293031": BEEP 0.05,20
   20 INPUT "MONTH (1-12):";A: IF (A<1)+(A>12) THEN GO TO 20
   30 INPUT "YEAR (YYYY):";B: IF B<1582 THEN BEEP 1,-20: GO TO 30
   60 LET B=INT B: LET E=B-(A<3)
   65 LET C=A+12*(A<3)+1
   70 LET D=INT (E/400)-INT (E/100)+INT (1.25*E)+INT (2.6*C)
   75 LET D=D-(7*INT (D/7))+1
   80 IF (A=4)+(A=6)+(A=9)+(A=11) THEN LET C=30
   85 IF (A=1)+(A=3)+(A=5)+(A=7)+(A=8)+(A=10)+(A=12) THEN LET C=31
   90 IF A<>2 THEN GO TO 200
  100 LET C=28: IF (B/4=INT (B/4))*(B/100<>INT (B/100))+(B/400=INT (B/400)) THEN LET C=29
  200 PLOT 10,132: DRAW 225,0: DRAW 0,-112: DRAW -225,0: DRAW 0,112
  210 PLOT 10,118: DRAW 225,0
  220 PRINT AT 6,3;"S   M   T   W  Th   F   S": PRINT AT 3,0;
  230 FOR Z=1 TO 6: PLOT 10,116-(Z-1)*16: DRAW 225,0: NEXT Z
  240 FOR Z=1 TO 6: PLOT 40+(Z-1)*32,132: DRAW 0,-112: NEXT Z
  250 RESTORE : FOR Z=1 TO 12: READ M$(Z): NEXT Z
  252 PRINT TAB 8;M$(A);TAB 18;B
  264 DIM C$(74): LET J=8: LET K=2: LET C$=C$( TO 2*D-2)+Z$
  270 FOR Z=1 TO C+D-1: PRINT AT J,K;C$(2*Z-1 TO 2*Z): LET K=K+4
  280 IF (Z/7=INT (Z/7)) THEN LET J=J+2: LET K=2
  290 NEXT Z: STOP : STOP 
  300 DATA "JANUARY","FEBRUARY","MARCH","APRIL","MAY","JUNE","JULY","AUGUST","SEPTEMBER","OCTOBER","NOVEMBER","DECEMBER"
  999 SAVE "cal" LINE 8
```