A: Minor system changes are made outside of core business hours every few weeks. Major or significant updates are scheduled, typically quarterly outside core business hours, and communicated to clients in advance.
During critical times of the tax calendar, such as year end and 1042s filing season (up to and shortly after March 15th) changes to the system are limited to those deemed essential, with everything else put on hold until after key tax and reporting cycles.
System enhancements and updates generally do not affect usage of the software.