Overview
When using Export to CSV to download a report that contains date columns, and you import that CSV into a Microsoft Excel or Google Sheet, you experience that some dates or times are apparently wrongly formatted (not recognized as date time).
Solution
The issue is due to the difference between your computer's date-time format configured in regional settings and the date-time format configured by you in FogBugz.
To have the exported CSV correctly formatted when opened in Microsoft Excel or Google Sheets, make sure that the two are the same.
Instructions for setting date-time format depending on your operating system type: