diff --git a/tools/check-node-fixtures b/tools/check-node-fixtures
index 7fa1e63a6c..edf342df2c 100755
--- a/tools/check-node-fixtures
+++ b/tools/check-node-fixtures
@@ -42,10 +42,11 @@ os.environ["DJANGO_SETTINGS_MODULE"] = "zproject.test_settings"
 django.setup()
 
 from zerver.lib import event_schema
-from zerver.lib.data_types import (  # force vertical
+from zerver.lib.data_types import (
     DictType,
     EnumType,
     ListType,
+    NumberType,
     UnionType,
     make_checker,
     schema,
@@ -150,7 +151,7 @@ def from_openapi(node: Dict[str, Any]) -> Any:
         return int
 
     if node["type"] == "number":
-        return float
+        return NumberType()
 
     if node["type"] == "string":
         if "enum" in node:
diff --git a/zerver/lib/data_types.py b/zerver/lib/data_types.py
index 0a143fdb42..af190a92eb 100644
--- a/zerver/lib/data_types.py
+++ b/zerver/lib/data_types.py
@@ -93,6 +93,16 @@ class Equals:
         return f"{var_name} in {repr([self.expected_value])}"
 
 
+class NumberType:
+    def check_data(self, var_name: str, val: Optional[Any]) -> None:
+        if isinstance(val, int) or isinstance(val, float):
+            return
+        raise AssertionError(f"{var_name} is not a number")
+
+    def schema(self, var_name: str) -> str:
+        return f"{var_name}: number"
+
+
 class ListType:
     def __init__(self, sub_type: Any, length: Optional[int] = None) -> None:
         self.sub_type = sub_type
diff --git a/zerver/lib/event_schema.py b/zerver/lib/event_schema.py
index 6a37f72faa..b628cfdcae 100644
--- a/zerver/lib/event_schema.py
+++ b/zerver/lib/event_schema.py
@@ -12,6 +12,7 @@ from zerver.lib.data_types import (
     EnumType,
     Equals,
     ListType,
+    NumberType,
     OptionalType,
     UnionType,
     UrlType,
@@ -166,6 +167,25 @@ default_streams_event = event_dict_type(
 )
 check_default_streams = make_checker(default_streams_event)
 
+_hotspot = DictType(
+    required_keys=[
+        # force vertical
+        ("name", str),
+        ("title", str),
+        ("description", str),
+        ("delay", NumberType()),
+    ]
+)
+
+hotspots_event = event_dict_type(
+    required_keys=[
+        # force vertical
+        ("type", Equals("hotspots")),
+        ("hotspots", ListType(_hotspot),),
+    ]
+)
+check_hotspots = make_checker(hotspots_event)
+
 invites_changed_event = event_dict_type(
     required_keys=[
         # the most boring event...no metadata
diff --git a/zerver/tests/test_data_types.py b/zerver/tests/test_data_types.py
index 10c9a700e8..04765d74c9 100644
--- a/zerver/tests/test_data_types.py
+++ b/zerver/tests/test_data_types.py
@@ -3,6 +3,7 @@ from zerver.lib.data_types import (
     EnumType,
     Equals,
     ListType,
+    NumberType,
     OptionalType,
     UnionType,
     UrlType,
@@ -22,6 +23,7 @@ class MiscTest(ZulipTestCase):
                 ("type", Equals("realm")),
                 ("maybe_n", OptionalType(int)),
                 ("s", str),
+                ("timestamp", NumberType()),
                 ("flag", bool),
                 ("level", EnumType([1, 2, 3])),
                 ("lst", ListType(int)),
@@ -37,6 +39,7 @@ test (dict):
         type: int
     maybe_n: int
     s: str
+    timestamp: number
     type in ['realm']
     url: str
     value (union):
diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 516e9ce1dd..3ccc9493ad 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -95,6 +95,7 @@ from zerver.lib.event_schema import (
     check_default_stream_groups,
     check_default_streams,
     check_events_dict,
+    check_hotspots,
     check_invites_changed,
     check_message,
     check_reaction,
@@ -1607,18 +1608,9 @@ class NormalActionsTest(BaseAction):
         self.user_profile.tutorial_status = UserProfile.TUTORIAL_WAITING
         self.user_profile.save(update_fields=['tutorial_status'])
 
-        schema_checker = check_events_dict([
-            ('type', equals('hotspots')),
-            ('hotspots', check_list(check_dict_only([
-                ('name', check_string),
-                ('title', check_string),
-                ('description', check_string),
-                ('delay', check_float),
-            ]))),
-        ])
         events = self.verify_action(
             lambda: do_mark_hotspot_as_read(self.user_profile, 'intro_reply'))
-        schema_checker('events[0]', events[0])
+        check_hotspots('events[0]', events[0])
 
     def test_rename_stream(self) -> None:
         stream = self.make_stream('old_name')