Data update

Task/Five-weekends/PascalABC.NET/five-weekends.pas

@@ -0,0 +1,27 @@
+uses system;
+
+const
+  startYear = 1900;
+  endYear = 2100;
+
+begin
+  var query := new List<datetime>;
+  foreach var year in (startyear..endyear) do
+    foreach var month in (1..12) do
+      if DateTime.DaysInMonth(year, month) = 31 then
+        query.Add(new DateTime(year, month, 1));
+  query := query.where(d -> d.dayofweek = dayofweek.Friday).ToList;
+
+  println('Count:', query.Count);
+  println;
+  println('First five:');
+  foreach var date in query.Take(5) do
+    writeln(date.Year, '-', date.Month);
+  println;
+  Println('Last five:');
+  foreach var date in query.Skip(query.Count - 5) do
+    writeln(date.Year, '-', date.Month);
+  println;
+  println('Years without 5 weekends:');
+  (startyear..endyear).except(query.Select(d -> d.year)).Println
+end.