Wookiepedia states that the series is to take place 7 years after A New Hope
; CNET claims that it will be set 7 years after Return of the Jedi.
My understanding is our timeline is now 19 years after the events of A New Hope
(which puts us smack dab in between the end of Return of the Jedi
and the beginning of The Force Awakens
). I think the biggest impact the Mandalorian
will have is that it is purported to show the beginnings of the First Order.