QuickViz. Change date format of output file to ISO

wimcollect/quickviz.py

@@ -41,7 +41,7 @@ class Visualizator:
         calib_filename = site_id + "_" + picarro_id + "_" + day.strftime("%Y%m%d") + ".csv"
         calib_filepath = os.path.join(calib_dir, calib_filename)
 
-        df.to_csv(calib_filepath, index=False)
+        df.to_csv(calib_filepath, index=False, date_format='%Y-%m-%dT%H:%M:%S.%fZ')
 
     def get_data(self, dat_files: list) -> pd.DataFrame:
         dateparse = lambda x: pd.datetime.strptime(x, '%Y-%m-%d %H:%M:%S.%f')