One way you can find out when a volume was created is using powershell toolkit. After you connect to the controller use the cmdlet Mount-NaController, then browse the controller using "cd controller_name_or_ip:", "cd vol", "ls". You should get a list of all the volumes and the "Created" column shows the date when a vol was created.
hope that helped,
On filer command mode please use the below command to see the creation time/modificaiton time and last access time of volume.
<filer> flexcache fstat <volume name>
If you will use the above command then you need not to mount the volume and use the command called cd
Hope this is the perfect answer what you are looking.