Add tasks for all the new languages

Task/Calendar/Sidef/calendar.sidef

@@ -0,0 +1,52 @@
+require('DateTime')
+
+define months_per_col = 3
+define week_day_names = <Mo Tu We Th Fr Sa Su>
+define month_names = <Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec>
+
+func fmt_month (year, month) {
+    var str = sprintf("%-20s\n", month_names[month-1])
+    str += week_day_names.join(' ')+"\n"
+
+    var dt = %s'DateTime'
+    var date = dt.new(year => year, month => month)
+    var week_day = date.day_of_week
+    str += (["  "] * week_day-1 -> join(" "))
+
+    var last_day = dt.last_day_of_month(year => year, month => month).day
+    for day in range(date.day, last_day) {
+        date = dt.new(year => year, month => month, day => day)
+
+        str += " " if (week_day ~~ range(2,7))
+        if (week_day == 8) {
+            str += "\n"
+            week_day = 1
+        }
+        str += sprintf("%2d", day)
+        ++week_day
+    }
+    str += " " if (week_day < 8)
+    str += (["  "] * 8-week_day -> join(" "))
+    str += "\n"
+}
+
+func fmt_year (year) {
+    var month_strs = 12.of { |i| fmt_month(year, i).lines }
+
+    var str = (' '*30 + year + "\n")
+    for month in range(0, 11, months_per_col) {
+        while (month_strs[month]) {
+            months_per_col.times { |i|
+                month_strs[month + i - 1] || next
+                str += month_strs[month + i - 1].shift
+                str += ' '*3
+            }
+            str += "\n"
+        }
+        str += "\n"
+    }
+
+    return str
+}
+
+print fmt_year(ARGV.is_empty ? 1969 : ARGV[0].to_i)