Palindromic Dates

[Qwerkey]

Apparently February 2nd was "International Palindrome Day" because the date was 02/02/2020.  Luckily this is palindromic in both British configuration (DD/MM/YYYY) and American configuration (MM/DD/YYYY).

So I thought that I'd find out which dates have been palindromic.  The program gives a list of palindromic dates from year 0 to 2100.  British date configuration is used, but you can easily adapt it to American configuration.  A text file is created as well as print to screen as there are, not surprisingly, quite a few such dates.

Code: QB64: [Select]

1. 'Palindromic Dates (British Date Configuration DDMMYYYY) 05/02/2020 by Qwerkey
2. '02022020 was palindromic
3. 'Do up to 2100 (assuming gregorian calendar goes back to zero)
4.  
5. CONST False = 0, True = NOT False
6.  
7. DIM Months%%(12)
8. FOR N%% = 1 TO 12
9.     READ Months%%(N%%)
10. NEXT N%%
11.  
12. OPEN "palindate.txt" FOR OUTPUT AS #1
13.  
14. Day%% = 1
15. Month%% = 1
16. Year% = 0
17.  
18. WHILE Year% < 2101
19.     Palin$ = DayMonth$(Day%%) + DayMonth$(Month%%) + Annus$(Year%)
20.     IF IsPalindromic%%(Palin$) THEN
21.         PRINT Palin$
22.         PRINT #1, Palin$
23.     END IF
24.     Day%% = Day%% + 1
25.     IF Day%% > Months%%(Month%%) THEN
26.         Day%% = 1
27.         Month%% = Month%% + 1
28.         IF Month%% > 12 THEN
29.             Month%% = 1
30.             Year% = Year% + 1
31.             'Modification for leap years:
32.             IF Year% \ 4 = Year% / 4 THEN
33.                 Months%%(2) = 29
34.                 IF Year% \ 400 = Year% / 400 THEN Months%%(2) = 28
35.             ELSE
36.                 Months%%(2) = 28
37.             END IF
38.         END IF
39.     END IF
40. WEND
41.  
42. CLOSE #1
43.  
44. FUNCTION IsPalindromic%% (P$)
45.     IsPalindromic%% = True
46.     M%% = 1
47.     WHILE M%% <= 4 AND IsPalindromic%%
48.         IF MID$(P$, M%%, 1) <> MID$(P$, 9 - M%%, 1) THEN IsPalindromic%% = False
49.         M%% = M%% + 1
50.     WEND
51. END FUNCTION
52.  
53. FUNCTION DayMonth$ (M%%)
54.     S$ = LTRIM$(STR$(M%%))
55.     IF M%% < 10 THEN
56.         DayMonth$ = "0" + S$
57.     ELSE
58.         DayMonth$ = S$
59.     END IF
60. END FUNCTION
61.  
62. FUNCTION Annus$ (Y%)
63.     A$ = LTRIM$(STR$(Y%))
64.     IF Y% < 10 THEN
65.         Annus$ = "000" + A$
66.     ELSEIF Y% < 100 THEN
67.         Annus$ = "00" + A$
68.     ELSEIF Y% < 1000 THEN
69.         Annus$ = "0" + A$
70.     ELSE
71.         Annus$ = A$
72.     END IF
73. END FUNCTION
74.  
75. DATA 31,28,31,30,31,30,31,31,30,31,30,31
76.  

[bplus]

Wait Groundhog Day, Superbowl Day AND Palindrome Day with BOTH British and American date configurations!

Were all the planets lined up as well? No, just the Republicans. Oh, and the Democrats. ;-))

[Qwerkey]

Groundhog Day.  The other day my wife and I asked ourselves "what exactly is Groundhog Day?".  Wikipedia says: "It derives from the Pennsylvania Dutch superstition that if a groundhog emerging from its burrow on this day sees its shadow due to clear weather, it will retreat to its den and winter will persist for six more weeks, and if it does not see its shadow because of cloudiness, spring will arrive early.".  This is a thing that you North Americans want to celebrate??? You're a lot stranger than we thought!

... just the Republicans.  Oh no! Don't set Pete off, please!

[Dimster]

And Guy Fawkes Day is completely sane? 11/5 2020 - 5/11/2020 may not be Palindromic but perhaps Pedantic. He says holding a flaming torch, glazed eyes and a Capital building in front of him.