make this a seasonal easter egg

OpenRA.Mods.RA/OpenRA.Mods.RA.csproj

@@ -570,6 +570,7 @@
     <Compile Include="Warheads\PerCellDamageWarhead.cs" />
     <Compile Include="Warheads\SpreadDamageWarhead.cs" />
     <Compile Include="Scripting\Global\ReinforcementsGlobal.cs" />
+    <Compile Include="Scripting\Global\DateGlobal.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRA.Game\OpenRA.Game.csproj">

OpenRA.Mods.RA/Scripting/Global/DateGlobal.cs

@@ -0,0 +1,28 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using Eluant;
+using OpenRA.Scripting;
+
+namespace OpenRA.Mods.RA.Scripting
+{
+	[ScriptGlobal("Date")]
+	public class DateGlobal : ScriptGlobal
+	{
+		public DateGlobal(ScriptContext context) : base(context) { }
+
+		[Desc("True on the 31st of October.")]
+		public bool Halloween
+		{
+			get { return DateTime.Today.Month == 10 && DateTime.Today.Day == 31; }
+		}
+	}
+}

mods/ra/maps/desert-shellmap/desert-shellmap.lua

@@ -1,6 +1,4 @@
-local ants = Utils.RandomInteger(0, 51) == 0
-
-if ants then
+if Date.Halloween then
 	UnitTypes = { "ant", "ant", "ant" }
 	BeachUnitTypes = { "ant", "ant" }
 	ParadropUnitTypes = { "ant", "ant", "ant", "ant", "ant" }