Importing Cisco WSA (IronPort) access logs into WebSpy Vantage using the default log format may result in your reports displaying the wrong time of day.
This is due to the default %t date/time field records the date and time in GMT, not local time.
You can use of the Time Offset feature in Vantage to adjusts the date and time when importing, however you need to remember to adjust the time offset for daylight savings time.
Fortunately, Cisco WSA (IronPort) can be configured to log local time instead of GMT. This is done using the %L date/time field instead of the default %t date/time field.
To do this, go to System Administration | Log Subscriptions | Access Logs and ensure %L is in the Field Modifiers edit box.
While you're there, you may also like to include in some other useful fields for web reporting such as Referrer URL and MimeType. You'll then be able to clean up your web reports using the IronPort Custom Expression described in Making Sensible Employee Internet Reports for the Modern Web (Part 5).
Please see your IronPort documentation for more information on adding new fields to your log data.
Traffic showing as the wrong time of the day
Ironport Access logs