NOTE: this does not relate to Devices that are not updating. This relates to Devices that are updating, but have incorrect timed updates.

If all Assets are updating with the incorrect time, this is probably due to either 

(1) all devices configured to a time zone other than GMT, or 

(2) the time zone of the User in question is incorrect.

For (1) configuration please update this to GMT.

To check (2) the Time Zone of the User, click on the down arrow next to the User name:

To adjust the Time Zone, if incorrect, navigate to Administration, choose the Client (or Vendor or Distributor) Account , the Users folder, and choose the relevant User by double clicking their name. The Time Zone setting is displayed under the Details tab. Click Edit next to their name, and choose the correct Time Zone from the list.