The time left is shown in the Current Task information in the rendering window, but the Time Remaining field in the Rendering Progress displays “??:??:??”, screenshot attached.
EDIT - Estimated remaining updates properly in the Stats tab in the VFB, just as extra info.
I think it’s meant for sequence rendering, not for single frames.
Must admit I don’t recall, a user was asking about it on Facebook - I’ll have to roll back and see if it was always that way, I never pay attention to that field myself 
try if it works for animations 
It sure does, so that’s what it’s for Can close this one out!
