ThoughtSpot comes configured with the timezone where it is to be installed. Data is imported based on the timezone of the node from which tsload or tql is run. To see the timezone your ThoughtSpot node is running under, log in to the server as the thoughtspot user and run the date command:

[thoughtspot@ts.server etc]$ date
Tue Feb 20 09:07:04 PST 2018

To see the current timezone used by the ThoughtSpot application, choose Admin > Cluster Manager and review the Cluster Details:

The timezones should match.

Sometimes the timezone that is listed by date is not the active timezone for the ThoughtSpot application and the application needs to be reset. If you need to change the timezone, contact ThoughtSpot Support and they will change the timezone for you. You may need to change the timezone if you move the server between data centers.