diff --git a/src/rc_gpfs/utils/datetime.py b/src/rc_gpfs/utils/datetime.py
index 13933b9554b44d3a3c82abe47c4b93a51e4cf6ec..2f5067adb35e18c73b1ce40b22f1a4464aa32b37 100644
--- a/src/rc_gpfs/utils/datetime.py
+++ b/src/rc_gpfs/utils/datetime.py
@@ -30,6 +30,11 @@ def create_timedelta_labels(
 ) -> List[str]:
     if not isinstance(delta_vals,list):
         delta_vals=[delta_vals]
+    
+    delta_vals = [v for v in delta_vals if v > 0]
+
+    if len(delta_vals) == 0:
+        raise ValueError('Passed delta_vals are all less than or equal to 0. delta_vals must be positive integers')
     delta_vals.sort(reverse=True)
     deltas = [f'{d}{delta_unit}' for d in delta_vals]