The History Explore in System Activity does not expose the Updated At (or equivalent) field under the Dashboard view. As a result, it is not possible to filter or sort dashboards by their last modification date directly from this Explore.
Notably, the Updated At field does exist in the History Explore for the Look view — confirming the field is not globally absent from History, but is specifically missing for the Dashboard view only.
This field is available in other System Activity Explores (e.g. the Dashboard Explore), but its absence in History prevents users from correlating dashboard updates with the associated query history.