To configure NTP functionality, browse to System → Time settings. The first tab time settings allows you to configure three NTP servers that will be used by the system query time from. Don't forget to set the Time-zone dropdown to the correct value, otherwise UTC will be assumed and used. Click Update (at the bottom of page) to save.

The easiest way of verifying time settings is simply looking at the displayed time stamp in the bottom right corner of the HSMX management web-interface. This will 'jump' to the right hour/time when saving the time settings configuration.