Where can I find J2EE application's deployment date and time in websphere application server's admin console?
I don't believe the install date is explicitly recorded anywhere.
However, as an unsupported trick, you can use the timestamps that are embedded in the configuration ids in deployment.xml.
Looking at the deplyment.xml file
PROFILE_HOME/config/cells/cell/applications/APP.ear/deployments/APP/deployment.xml
the root element will look something like:
<appdeployment:Deployment
xmi:version="2.0"
xmlns:xmi="http://www.omg.org/XMI" xmlns:appdeployment="http://www.ibm.com/websphere/appserver/schemas/5.0/appdeployment.xmi"
xmi:id="Deployment_1326844745277">
The suffix of xmi:id
is System.currentTimeMillis():
$ perl -e 'print scalar(localtime(1326844745277 / 1000)), "\n"'
Tue Jan 17 17:59:05 2012