Index: binaries/data/mods/public/simulation/components/Timer.js
===================================================================
--- binaries/data/mods/public/simulation/components/Timer.js
+++ binaries/data/mods/public/simulation/components/Timer.js
@@ -20,6 +20,35 @@
 };
 
 /**
+ * Gives the timers belonging to a specific entity.
+ *
+ * @param {number} entity - The entity ID of the entity to return the timers for.
+ *
+ * @return {Object[]} - An array of the timers which the entity has.
+ */
+Timer.prototype.GetTimers = function(entity)
+{
+	let timers = {};
+	for (let [id, timer] of this.timers)
+		if (timer.entity == entity)
+			timers[id] = timer;
+	return timers;
+};
+
+/**
+ * Transfers a timer from an entity to a new entity, e.g. when promoting.
+ *
+ * @param {number} timerID - The timer ID to be transfered.
+ * @param {number} newEnt - The entity ID of the entity to which the timer ought to be transferred.
+ */
+Timer.prototype.TransferTimer = function(timerID, newEnt)
+{
+	for (let [id, timer] of this.timers)
+		if (id == timerID)
+			timer.entity = newEnt;
+};
+
+/**
  * Returns the duration of the latest turn in milliseconds.
  */
 Timer.prototype.GetLatestTurnLength = function()
Index: binaries/data/mods/public/simulation/components/tests/test_Pack.js
===================================================================
--- binaries/data/mods/public/simulation/components/tests/test_Pack.js
+++ binaries/data/mods/public/simulation/components/tests/test_Pack.js
@@ -39,7 +39,8 @@
 
 AddMock(SYSTEM_ENTITY, IID_Timer, {
 	"CancelTimer": id => { timerActivated = false; return; },
-	"SetInterval": (ent, iid, funcname, time, repeattime, data) => { timerActivated = true; return 7; }
+	"SetInterval": (ent, iid, funcname, time, repeattime, data) => { timerActivated = true; return 7; },
+	"GetTimers": () => []
 });
 
 Engine.AddEntity = function(template) {
Index: binaries/data/mods/public/simulation/components/tests/test_Timer.js
===================================================================
--- binaries/data/mods/public/simulation/components/tests/test_Timer.js
+++ binaries/data/mods/public/simulation/components/tests/test_Timer.js
@@ -78,3 +78,10 @@
 
 cmpTimer.OnUpdate({ "turnLength": 3.0 });
 TS_ASSERT_UNEVAL_EQUALS(fired, [["s",2500]]);
+
+fired = [];
+
+let t = cmpTimer.SetTimeout(10, IID_Test, "Callback", 1000, "t");
+cmpTimer.TransferTimer(t, 20);
+cmpTimer.OnUpdate({ "turnLength": 1.0 });
+TS_ASSERT_UNEVAL_EQUALS(fired, [["t",0]]);
Index: binaries/data/mods/public/simulation/helpers/Transform.js
===================================================================
--- binaries/data/mods/public/simulation/helpers/Transform.js
+++ binaries/data/mods/public/simulation/helpers/Transform.js
@@ -109,6 +109,7 @@
 		}
 	}
 
+	TransferTimers(oldEnt, newEnt);
 	TransferGarrisonedUnits(oldEnt, newEnt);
 
 	Engine.PostMessage(oldEnt, MT_EntityRenamed, { "entity": oldEnt, "newentity": newEnt });
@@ -256,6 +257,21 @@
 	}
 }
 
+/**
+ * Transfers timers from oldEnt to newEnt.
+ *
+ * @param {number} oldEnt - The entity ID of the entity to transfer the timer from.
+ * @param {number} newEnt - The entity ID of the entity to transfer the timer to.
+ */
+function TransferTimers(oldEnt, newEnt)
+{
+	let cmpTimer = Engine.QueryInterface(SYSTEM_ENTITY, IID_Timer);
+	let timers = cmpTimer.GetTimers(oldEnt);
+	for (let timer in timers)
+		if (Engine.QueryInterface(newEnt, timers[timer].iid))
+			cmpTimer.TransferTimer(timer, newEnt);
+}
+
 Engine.RegisterGlobal("ChangeEntityTemplate", ChangeEntityTemplate);
 Engine.RegisterGlobal("CanGarrisonedChangeTemplate", CanGarrisonedChangeTemplate);
 Engine.RegisterGlobal("ObstructionsBlockingTemplateChange", ObstructionsBlockingTemplateChange);