Wrap timedelta as list

src/rc_gpfs/utils/datetime.py

@@ -19,6 +19,8 @@ def create_timedelta_breakpoints(
     delta_vals: int | List[int],
     delta_unit: Literal['D','W']
 ) -> List[np.datetime64]:
+    if not isinstance(delta_vals,list):
+        delta_vals=[delta_vals]
     run_date = as_datetime(run_date)
     return [run_date - as_timedelta(c,delta_unit) for c in delta_vals if c > 0]