code: def getTimes(dataTasks):
      
      global begin_time
      start_time, end_time = float('inf'), 0
      for fichier, vals in dataTask.items():
          try:
              if hasattr(vals, 'values'):
                  tmp_start_time = min([a['start_time'] for a in vals.values()])[0]
                  if tmp_start_time < start_time:
                      start_time = tmp_start_time
                  tmp_end_time = max([a['end_time'] for a in vals.values()])[0]
                  if tmp_end_time > end_time:
                      end_time = tmp_end_time
          except ValueError:
              continue
      begin_time = 1000 * start_time
      return 1000 * start_time, 1000 * end_time
docs: Get the start time and the end time of data in milliseconds