For example what time did I install this package?
1. Auto Email Inactive Users 1.7 - 01.07.2099/21:30 [ Remove ]
2. Activity_Bar 1.0.1 - 30.06.2009/22:15 [ Remove ]
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You would have to store the date in the database...
I don't know, you know better than me how it will be create?
The packages directory on your ftp will have the date and timestamp of when the package was uploaded.
The only problem is that you may not have actually INSTALLED it at the time of upload. For me this is only the case maybe 1 in 10 times so it's fairly accurate.