diff --git a/pysurfex/datetime_utils.py b/pysurfex/datetime_utils.py
index 7eb68de..56d9e22 100644
--- a/pysurfex/datetime_utils.py
+++ b/pysurfex/datetime_utils.py
@@ -23,6 +23,11 @@ def as_datetime_string(dtg):
     return dtg.strftime(fmt)
 
 
+def offsetaware(dtg):
+    """Make offset aware."""
+    return dtg.replace(tzinfo=timezone.utc)
+
+
 def as_timedelta(seconds=0):
     """Convert seconds to timedelta."""
     return timedelta(seconds=seconds)
diff --git a/pysurfex/namelist.py b/pysurfex/namelist.py
index df1dbfb..ce96fb6 100644
--- a/pysurfex/namelist.py
+++ b/pysurfex/namelist.py
@@ -24,30 +24,6 @@ def __init__(self, program, config, definitions, assemble=None, consistency=True
         self.program = program
         self.config = config
         self.nldict = definitions
-        """
-        macros_defs = {
-            "CPGDFILE": "SURFEX#IO#CPGDFILE",
-            "CPREPFILE": "SURFEX#IO#CPREPFILE",
-            "CSURFFILE": "SURFEX#IO#CSURFFILE",
-            "CSURF_FILETYPE": "SURFEX#IO#CSURF_FILETYPE",
-            "CFORCING_FILETYPE": "SURFEX#IO#CFORCING_FILETYPE",
-            "CTIMESERIES_FILETYPE": "SURFEX#IO#CTIMESERIES_FILETYPE",
-            "XRIMAX": "SURFEX#PARAMETERS#XRIMAX",
-            "LSPLIT_PATCH": "SURFEX#IO#LSPLIT_PATCH",
-            "LFAKETREE": "SURFEX#TREEDRAG#FAKETREES",
-            "LECOSG": "SURFEX#COVER#SG",
-            "XTSTEP": "SURFEX#IO#XTSTEP",
-            "XTSTEP_OUTPUT ": "SURFEX#IO#XTSTEP_OUTPUT",
-        }
-        macros = {}
-        for macro, setting in macros_defs.items():
-            vmacro = config.get_setting(setting)
-            logging.debug("Mapping macro %s = %s", macro, vmacro)
-            if vmacro is not None:
-                if isinstance(vmacro, tuple):
-                    vmacro = list(vmacro)
-                macros.update({macro: vmacro})
-        """
 
         nobstype = 0
         if program == "soda" or program == "offline":
diff --git a/pysurfex/netcdf.py b/pysurfex/netcdf.py
index b12acbf..16bf74c 100644
--- a/pysurfex/netcdf.py
+++ b/pysurfex/netcdf.py
@@ -17,7 +17,7 @@
     cfunits = None
 
 
-from .datetime_utils import fromtimestamp, isdatetime, utcfromtimestamp
+from .datetime_utils import fromtimestamp, isdatetime, offsetaware, utcfromtimestamp
 from .geo import ConfProj, Geo
 from .interpolation import Interpolation
 
@@ -102,6 +102,7 @@ def nc_slice(
                 logging.debug("Time provided in call as datetime objects")
                 times_in_var = var.datetimes
                 for i, times_in_var_val in enumerate(times_in_var):
+                    times_in_var_val = offsetaware(times_in_var_val)
                     logging.debug(
                         "i %s times_in_var %s times %s", i, times_in_var_val, times
                     )
@@ -110,7 +111,7 @@ def nc_slice(
                         logging.debug(
                             "i=%s, times_in_var_val=%s tval=%s", i, times_in_var_val, tval
                         )
-                        if times_in_var[i] == tval:
+                        if times_in_var_val == tval:
                             times_to_read.append(i)
                             if i > 0:
                                 prev_time_steps.append(i - 1)
diff --git a/pysurfex/run.py b/pysurfex/run.py
index be48a8b..00e99ba 100644
--- a/pysurfex/run.py
+++ b/pysurfex/run.py
@@ -196,27 +196,19 @@ def __init__(
             negpert (bool, optional): _description_. Defaults to False.
 
         """
-        self.pert_number = pert_number
+        pert_number = int(pert_number)
         settings["nam_io_varassim"]["LPRT"] = True
-        settings["nam_var"]["nivar"] = int(pert_number)
+        settings["nam_var"]["nivar"] = pert_number
         # Handle negative pertubations
         if negpert:
-            nvar = int(settings["nam_var"]["nvar"])
-            ipert = 0
-            npert = 1
-            for nvi in range(0, nvar):
-                key = "nncv(" + str(nvi + 1) + ")"
-                val = int(settings["nam_var"][key])
-                # Check if active
-                if val == 1:
-                    npert = 1
-                else:
-                    npert = npert + 1
-                for __ in range(0, npert):
-                    ipert = ipert + 1
-                    key = "xtprt_m(" + str(ipert) + ")"
-                    val = settings["nam_var"][key]
-                    settings["nam_var"][key] = -val
+            nncv = settings["nam_var"]["nncv"]
+            nind = 0
+            for nvi, nval in enumerate(nncv):
+                if nval == 1:
+                    nind += 1
+                    if nind == pert_number:
+                        val = settings["nam_var"]["xtprt_m"][nvi]
+                        settings["nam_var"]["xtprt_m"][nvi] = -val
         SURFEXBinary.__init__(
             self,
             binary,