diff --git a/disco/types/user.py b/disco/types/user.py
index a971fc4..c91a4ea 100644
--- a/disco/types/user.py
+++ b/disco/types/user.py
@@ -93,9 +93,11 @@ class Timestamps(SlottedModel):
     start = Field(int)
     end = Field(int)
 
+    @cached_property
     def start_time(self):
         return datetime.utcfromtimestamp(self.start / 1000)
 
+    @cached_property
     def end_time(self):
         return datetime.utcfromtimestamp(self.end / 1000)