When documents are processed and rendered, they are done so with respect to timezone. This means that date and time sensitive metadata will be presented in context of the selected timezone and that any automatic date/time components will also be rendered in that timezone.
Example: Original email created/sent in EST at 5:00PM. Upon uploading, one selected this email to be processed in PST. The email would display in PST as being sent at 2:00PM, the metadata would reflect 2:00PM as well. One could download the original document in the document viewer, and this would display the original time zone of 5:00PM.
Changing the timezone in your project
In either the Account or Project settings, navigate to the 'Preferences' tab, then the 'Document Formatting and Processing Settings' section. Keep in mind that the selection setting is permanent after the first upload.
Of note: There are two timezone settings: the default setting on the account level, and the setting you can select on the project level (which is permanent after the first upload). If the project level setting differs from the default account level setting - the project level setting will override.
As a best practice, try to set the timezone setting to the place where the data originated from.