diff --git a/python/lvmecp/actor/actor.py b/python/lvmecp/actor/actor.py
index fa327c0..10047ff 100644
--- a/python/lvmecp/actor/actor.py
+++ b/python/lvmecp/actor/actor.py
@@ -31,9 +31,6 @@
 class ECPActor(LVMActor):
     """Enclosure actor."""
 
-    _engineering_mode_hearbeat_interval: float = 5
-    _engineering_mode_timeout: float = 30
-
     parser = parser
 
     def __init__(
@@ -69,6 +66,9 @@ def __init__(
         self._monitor_dome_task: asyncio.Task | None = None
 
         self._engineering_mode: bool = False
+        self._engineering_mode_hearbeat_interval: float = 5
+        self._engineering_mode_started_at: float | None = None
+        self._engineering_mode_duration: float | None = None
         self._engineering_mode_task: asyncio.Task | None = None
 
         self._last_heartbeat: float | None = None
@@ -162,14 +162,19 @@ async def _run_eng_mode(self, timeout: float | None = None):
 
         """
 
-        started_at: float = time.time()
-        if timeout is not None:
-            self._engineering_mode_timeout = timeout
+        eng_mode_config = self.config.get("engineering_mode", {})
+        default_duration = eng_mode_config.get("default_duration", 300)
+
+        self._engineering_mode_started_at = time.time()
+        self._engineering_mode_duration = timeout or default_duration
+        assert self._engineering_mode_duration is not None
 
         while True:
             await self.emit_heartbeat()
 
-            if time.time() - started_at > self._engineering_mode_timeout:
+            elapsed = time.time() - self._engineering_mode_started_at
+
+            if elapsed > self._engineering_mode_duration:
                 self.write("w", text="Engineering mode timed out and was disabled.")
                 await self.engineering_mode(False)
                 return
diff --git a/python/lvmecp/actor/commands/engineering.py b/python/lvmecp/actor/commands/engineering.py
index f415b5e..200f485 100644
--- a/python/lvmecp/actor/commands/engineering.py
+++ b/python/lvmecp/actor/commands/engineering.py
@@ -58,9 +58,18 @@ async def status(command: ECPCommand):
     """Returns the status of the engineering mode."""
 
     enabled = command.actor.is_engineering_mode_enabled()
-    timeout = command.actor._engineering_mode_timeout
+    started_at = command.actor._engineering_mode_started_at
+    duration = command.actor._engineering_mode_duration
+
+    if duration is None or started_at is None:
+        ends_at = None
+    else:
+        ends_at = started_at + duration
 
     return command.finish(
-        engineering_mode_enabled=enabled,
-        engineering_mode_timeout=timestamp_to_iso(timeout),
+        engineering_mode={
+            "enabled": enabled,
+            "started_at": timestamp_to_iso(started_at),
+            "ends_at": timestamp_to_iso(ends_at),
+        }
     )
diff --git a/python/lvmecp/etc/lvmecp.yml b/python/lvmecp/etc/lvmecp.yml
index 580ebe0..aa1d34f 100644
--- a/python/lvmecp/etc/lvmecp.yml
+++ b/python/lvmecp/etc/lvmecp.yml
@@ -317,6 +317,9 @@ hvac:
       address: 12
       mode: coil
 
+engineering_mode:
+  default_duration: 300
+
 actor:
   name: lvmecp
   host: localhost
diff --git a/python/lvmecp/etc/schema.json b/python/lvmecp/etc/schema.json
index b9b1961..f9cc03d 100644
--- a/python/lvmecp/etc/schema.json
+++ b/python/lvmecp/etc/schema.json
@@ -26,9 +26,18 @@
     "last_heartbeat_set": {
       "oneOf": [{ "type": "number" }, { "type": "null" }]
     },
-    "engineering_mode_enabled": { "type": "boolean" },
-    "engineering_mode_timeout": {
-      "oneOf": [{ "type": "string" }, { "type": "null" }]
+    "engineering_mode": {
+      "type": "object",
+      "properties": {
+        "enabled": { "type": "boolean" },
+        "started_at": {
+          "oneOf": [{ "type": "string" }, { "type": "null" }]
+        },
+        "ends_at": {
+          "oneOf": [{ "type": "string" }, { "type": "null" }]
+        }
+      },
+      "required": ["enabled", "started_at", "ends_at"]
     }
   },
   "additionalProperties": true
diff --git a/tests/test_command_engineering_mode.py b/tests/test_command_engineering_mode.py
index befb7a5..eb71539 100644
--- a/tests/test_command_engineering_mode.py
+++ b/tests/test_command_engineering_mode.py
@@ -24,7 +24,7 @@ async def test_command_engineering_mode_status(actor: ECPActor):
     await cmd
 
     assert cmd.status.did_succeed
-    assert cmd.replies.get("engineering_mode_enabled") is False
+    assert cmd.replies.get("engineering_mode")["enabled"] is False
 
 
 async def test_command_engineering_mode_enable(actor: ECPActor, mocker: MockerFixture):