As of RT 3.2.2, RT has built in support for time-based escalations and
notifications using the rt-crontool framework.
You can read more about setting up these notifications on the wiki at :
<http://wiki.bestpractical.com/index.cgi?TimedNotifications>
Tara Andrews built the implementation for Best Practical as part of
some work we’re doing for a customer. We’re excited to be able to share
it with the RT user community and appreciate any feedback folks might
have.
Best,
Jesse