diff --git a/reflex/utils/build.py b/reflex/utils/build.py
index 7a67ec32e..ff589244b 100644
--- a/reflex/utils/build.py
+++ b/reflex/utils/build.py
@@ -236,6 +236,9 @@ def setup_frontend(
     # Set the environment variables in client (env.json).
     set_env_json()
 
+    # update the last reflex run time.
+    prerequisites.set_last_reflex_run_time()
+
     # Disable the Next telemetry.
     if disable_telemetry:
         processes.new_process(
diff --git a/reflex/utils/prerequisites.py b/reflex/utils/prerequisites.py
index f9eb9a790..20ee08929 100644
--- a/reflex/utils/prerequisites.py
+++ b/reflex/utils/prerequisites.py
@@ -132,6 +132,21 @@ def get_or_set_last_reflex_version_check_datetime():
     return last_version_check_datetime
 
 
+def set_last_reflex_run_time():
+    """Set the last Reflex run time.
+
+    Returns:
+        The last time the reflex app was started.
+    """
+    reflex_json_file = get_web_dir() / constants.Reflex.JSON
+    if not reflex_json_file.exists():
+        return
+
+    data = json.loads(reflex_json_file.read_text())
+    data.update({"last_reflex_run_datetime": str(datetime.now())})
+    path_ops.update_json_file(reflex_json_file, data)
+
+
 def check_node_version() -> bool:
     """Check the version of Node.js.