When does Rage End?

[Gortle]

Can anyone tell me when does a barbarian end their rage, if they can't perceive any enemies?
Is it an instantaneous limitation that triggers at any time in anyone's turn? Or is it evaluated at the start of the Babarians turn?

Thanks.

[Goldryno]

I believe it would be at the start of the Barbarian's turn just based on the fact that despite things happening in a specific order we are actually assuming everything is happening during the same 6 second increment.

[Timeshadow]

I agree at the start of the Barb player's turn if there are no enemies to rage against then it ends.