-'dropdown.this_day' => 'este dia',
-'dropdown.this_week' => 'esta semana',
-'dropdown.last_week' => 'última semana',
-'dropdown.this_month' => 'este mês',
-'dropdown.last_month' => 'último mês',
-'dropdown.this_year' => 'este ano',
+// TODO: translate the following.
+// 'dropdown.current_day' => 'today',
+// 'dropdown.previous_day' => 'yesterday',
+'dropdown.selected_day' => 'dia',
+'dropdown.current_week' => 'esta semana',
+'dropdown.previous_week' => 'última semana',
+'dropdown.selected_week' => 'semana',
+'dropdown.current_month' => 'este mês',
+'dropdown.previous_month' => 'último mês',
+'dropdown.selected_month' => 'mês',
+'dropdown.current_year' => 'este ano',
+// TODO: translate the following.
+// 'dropdown.previous_year' => 'previous year',
+'dropdown.selected_year' => 'ano',