By default both client and server will check for updates once an hour.  You can manually check for updates as detailed here: KB195 - How do I manually synchronise the ESET Endpoint Encryption Client and Server?

For most users the default schedule and manual process will be fine.  If however you wish to increase or decrease the check intervals, follow the steps below:

Client

• In the ESET Endpoint Encryption (EEE) Server select the Workstations tree branch of the navigation tree (or team if you wish to update a specific group of machines).
• Select the Workstation Policy tab.
• In the Server Communication Settings section select the entry Background update check period.
• Click the Change Setting button.

• Specify the new interval in minutes.
• Click the OK button.

The update will affect all new machines that use the policy. To update existing machines in the server select them in the Workstations list and click the Update Policy button.

Server

To change the interval of update checks from the server to the cloud:

• Click the Control Panel button in the top right corner of the EEE Server. 
• Select your Organisation/Settings section in the left hand menu.
• In the Background Timer Intervals section, specify a new value for ESET Endpoint Encryption Server Deployment Sync Timer.
• Click the Save button