Hi Diane,
This can be changed
The Greeting Length for a Call Handler is determined by the COS of the person recording the Greeting. Have a look;
Class of Service Greetings Settings
The class of service greetings setting specifies the maximum length of greetings.
Subscribers > Class of Service > Greetings Page
Field Considerations
Maximum Greeting Length in Seconds
Select the recording length allowed to subscribers assigned to this COS for recording greetings.
The range is 1 to 999 seconds; the default is 90 seconds.
Cheers!
Rob