Data commit

Task/Doomsday-rule/Python/doomsday-rule.py

@@ -0,0 +1,29 @@
+from datetime import date
+from calendar import isleap
+
+def weekday(d):
+    days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
+            "Friday", "Saturday"]
+    dooms = [
+        [3, 7, 7, 4, 2, 6, 4, 1, 5, 3, 7, 5],
+        [4, 1, 7, 4, 2, 6, 4, 1, 5, 3, 7, 5]
+    ]
+
+    c = d.year // 100
+    r = d.year % 100
+    s = r // 12
+    t = r % 12
+    c_anchor = (5 * (c % 4) + 2) % 7
+    doomsday = (s + t + (t // 4) + c_anchor) % 7
+    anchorday = dooms[isleap(d.year)][d.month - 1]
+    weekday = (doomsday + d.day - anchorday + 7) % 7
+    return days[weekday]
+
+dates = [date(*x) for x in
+    [(1800, 1, 6), (1875, 3, 29), (1915, 12, 7), (1970, 12, 23),
+     (2043, 5, 14), (2077, 2, 12), (2101, 4, 2)]
+]
+
+for d in dates:
+    tense = "was" if d < date.today() else "is" if d == date.today() else "will be"
+    print("{} {} a {}".format(d.strftime("%B %d, %Y"), tense, weekday(d)))