Issue
When a user opens a ZIP file downloaded via zip download feature on Box, Windows File Explorer may display modified timestamps in an incorrect time zone.
Root Cause
The ZIP format has no notion of time zone information, making timestamps inherently ambiguous regarding time zones. Although time zone data can be stored in the Extra Field of a ZIP file, this field is optional and its handling depends on the tool used to read the ZIP file. Some tools respect the time zone field, while others do not. Based on our observation, Windows Explorer does not support reading the Extended Timestamp Extra Field; instead, it interprets timestamps as local time without any timezone adjustment. This causes displayed times to shift incorrectly if the ZIP file is opened in a time zone other than Pacific Time.
Resolution
To view the correct modified time, users can take one or more of the following actions:
- Use a tool that supports time zones, such as 7-Zip.
- Alternatively, extract the ZIP file using any tool; the modified timestamps of extracted files should then display correctly according to your local time zone.