by Geigerkind » Fri Dec 25, 2015 9:48 pm
The vanilla API does not give you those information. It does give you under some circumstances what buffs they have but not how long they last. Depending on application you can guess the duration, which is what some addons do. In MPOWA you can configure such a thing for example. But EnemyBuffTimers does it as well.
My Addons:
DPSMate - A combat analyzation tool (/viewtopic.php?f=63&t=38042)
Vanilla Consolidated Buff-Frames (/viewtopic.php?f=63&t=18189)
Modified Power Auras (/viewtopic.php?f=63&t=18251)