This configuration parameter specifies the interval between SNTP clock updates when you are using the Windows Time Service to keep the local system clock in sync with the domain the computer has joined.
In most cases, you set the polling interval using group policy.
If you are manually setting this parameter, the value is the base 2 logarithm of the time in seconds. For example, setting this parameter value to 6 sets the update interval to 64 seconds (26), and a value of 15 sets the update interval to 32768 seconds, or 9.1 hours. For example, to set the update interval to 256 seconds:
If the parameter is not explicitly defined in the configuration file or by group policy, its default value is 15 (9.1 hours).