Hi Liz,Thank you for reporting this problem. I like to suggest the fix to utils.js shown below, which has been checked into the app's GitHub site. Earlier in the code, nulls have been normalized to empty strings to simplify some other processing, so when we're cycling through the list of fields for the infowindow, we can check if the retrieved date field value is an empty string. The js.date module contains a list of date-conversion routines; I see in hindsight how that name is misleading.Regards,Mikefor (var index in infoWindowData) { var tr = document.createElement("tr"); tbody.appendChild(tr); switch (infoWindowData[index].DataType) { case "string": CreateTableRow(tr, infoWindowData[index].DisplayText, dojo.string.substitute(infoWindowData[index].AttributeValue, attributes)); break; case "date": // Extract the desired date field from the list of attributes. If the date is not available, the date field is an empty string var dateField = dojo.string.substitute(infoWindowData[index].AttributeValue, attributes); var dateString = showNullValueAs; if (dateField.length > 0) { var utcMilliseconds = Number(dateField); dateString = dojo.date.locale.format(date.utcToLocal(date.utcTimestampFromMs(utcMilliseconds)), { datePattern: formatDateAs, selector: "date" }); } CreateTableRow(tr, infoWindowData[index].DisplayText, dateString); break; } }