I want to find when an SSIS 2008 package was deployed under MSDB in an instance of SQL Server. In the table dbo.sysssispackages, I can see package creation date but where can I find the last modified/deployed date of a package?
The date an SSIS package was deployed to the MSDB is not tracked so you do not have the ability to know when a package was deployed, who performed this feat, etc.
With SQL Server 2012+ and the project deployment model, the SSISDB supports the ability to track when a project was deployed and by whom.
The best answer I have for you is much the same as Tab has just posted except I tied mine to VerBuild, which is a monotonically increasing number that VS updates whenever you save a package.
If it's absolutely crucial that you have this information, you could look at modifying msdb.dbo.sp_ssis_putpackage. That's definitely off the reservation so buyer beware, etc but depending on your appetite for risk, you could either extend dbo.sysssispackages by adding your custom columns there or create a new table dbo.sysssispackages_extended and there record who did what and when.