The date fields in the feature services coming ArcGIS for Server are displayed as the Unix datestamp for example, 1357687771000 instead of the usual date format for example, 04/27/2015 in ArcGIS Open Data's pop-up box.
Last Published: June 11, 2015ArcGIS Online
Bug ID Number
April 29, 2015
June 11, 2020
The bug has been fixed. See the Version Fixed and Additional Information, if applicable, for more information.