A question I get a lot is how to solve date formatting issues in CMSImport. Unless you are using SQL Server all imported values are of type string. So when you try to import date values the data layer will try to convert the value to a DateTime object, if it can’t parse the string you will see an error. These errors can be solved. Let’s take the following example from a Wordpress export file that can fail.
When mapping the value in CMSImport you can select the advanced mapping option, this will show the following mapping options if you map against a DateTime Property. As you can see you can specify a date format. Check the custom date formatting section for the exact formatting syntax. When you specify a format that exactly matches the string from your datasource(TIP use the refresh option to update the preview) CMSImport will use that format to convert the string to the DateTime object and all will import fine.
Hope this helps you!