Fix conversion to datetime

By converting to microsecond precision

Author: dnerini

pysteps/blending/utils.py

@@ -315,7 +315,7 @@ def decompose_NWP(
         )
 
     # Make a NetCDF file
-    output_date = f"{analysis_time.astype(datetime.datetime):%Y%m%d%H%M%S}"
+    output_date = f"{analysis_time.astype('datetime64[us]').astype(datetime.datetime):%Y%m%d%H%M%S}"
     outfn = Path(output_path) / f"cascade_{NWP_model}_{output_date}.nc"
     ncf = netCDF4.Dataset(outfn, "w", format="NETCDF4")
 
@@ -411,7 +411,7 @@ def compute_store_nwp_motion(
     """
 
     # Set the output file
-    output_date = f"{analysis_time.astype(datetime.datetime):%Y%m%d%H%M%S}"
+    output_date = f"{analysis_time.astype('datetime64[us]').astype(datetime.datetime):%Y%m%d%H%M%S}"
     outfn = Path(output_path) / f"motion_{nwp_model}_{output_date}.npy"
 
     # Get the velocity field per time step