diff --git a/src/rc_gpfs/utils/core.py b/src/rc_gpfs/utils/core.py
index 1409d4f2633ef35b457cd0ad55a55bcc9ede6d65..2596c4cc0a472977dac337842ce5ee1371859b44 100644
--- a/src/rc_gpfs/utils/core.py
+++ b/src/rc_gpfs/utils/core.py
@@ -70,9 +70,11 @@ def prep_age_distribution(
         age_breakpoints: int | List[int],
         time_unit: Literal['D','W']
 ) -> Tuple[List[np.datetime64],List[str]]:
-    if any([b < 0 for b in age_breakpoints]):
-        raise ValueError("Timestamp cannot be newer than the current date time")
-    age_breakpoints = list(set(age_breakpoints))
+    if not isinstance(age_breakpoints,list):
+        age_breakpoints = [age_breakpoints]
+    else:
+        age_breakpoints = list(set(age_breakpoints))
+    
     age_breakpoints.sort()
     age_breakpoints = [t for t in age_breakpoints if t > 0]