Date/time: now save global timestamp in the model, instead of relative

src/View/LateralContributionsAdisTS/Edit/Table.py

@@ -91,7 +91,7 @@ class TableModel(PamhyrTableModel):
                     value = timestamp_to_old_pamhyr_date_adists(int(v))
                 else:
                     value = format_datetime(
-                        self._start_date + timedelta(seconds=float(v))
+                        datetime(1970, 1, 1) + timedelta(seconds=float(v))
                     )
             else:
                 value = f"{v}"
@@ -111,7 +111,7 @@ class TableModel(PamhyrTableModel):
         try:
             if (self._data.header[column] == "time"
                     and self._opt_data == "date"):
-                value = self.date_to_elapsed_seconds(value)
+                value = self.date_to_timestamp(value)
 
             row = self.get_true_data_row(row)