Data update

Task/Doomsday-rule/UNIX-Shell/doomsday-rule.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+day-of-the-week()
+  if [[ "$1" =~ ([0-9]{4})-([0-9]{2})-([0-9]{2}) ]]
+  then
+    local -ra names=({Sun,Mon,Tues,Wednes,Thurs,Fri,Satur}day) doomsday=({37,41}7426415375)
+    local -i i c s t a b
+    local -i {year,month,day}=${BASH_REMATCH[++i]}
+    echo ${names[
+      c=year/100,
+      s=(year%100)/12,
+      t=(year % 100) % 12,
+      a=(5*(c%4)+2) % 7,
+      b=(s + t + (t / 4) + a ) % 7,
+      (b + day - ${doomsday[(year%4 == 0) && ((year%100) || (year%400 == 0))]:month-1:1} + 7) % 7
+    ]}
+  else return 1
+  fi
+
+for date in 1800-01-06 1875-03-29 1915-12-07 1970-12-23 2043-05-14 2077-02-12 2101-04-02
+do day-of-the-week "$date"
+done