It sounds like you need a way of
- running the a BIRT report, through the BIRT reporting engine,
- using scheduler to control execution of the report a on a particular schedule
- specifying output format
- and specifying how the output should be delivered in the scheduled job.
You could role your own or you could use a Reporting/BI server that already has all of those capabilities. Depending on your other needs, this may be overkill or exactly right. I am using SpagoBI for that exact purpose. SpagoBI supports BIRT as one of the reporting formats and engines. It uses the quartz scheduler, and does support emailing a PDF version of a report to a specific email address (or list). You might also look into iHub or other products.
http://www.spagobi.org/
http://birt.actuate.com/products/birt-ihub
In SpagoBI, you would deploy your BIRT report to the SpagoBI server from SpagoBI Studio. Then, in SpagoBI Server you would setup the parameters on the report document and create a schedule for the report. On the schedule, you would specify the parameters (if other than default), a schedule, output format, and how you want the output stored/sent.