# Surface of Last Scattering Spacelike or Timelike from us

As far I understand, the whole universe, at a redshift of 1100, became transparent to light, and the phenomenon occurred throughout the whole universe. It is in our past, not in our left or right direction, i.e, the interval is timelike, not spacelike. If this is true, then why do we call it the surface of last scattering instead of redshift/time of last scattering? What is the meaning of "distance of last scattering surface" from us if it was in our past, not at left or right direction? How is the distance calculated and how do we measure the angular diameter($$2^{\circ}$$) of the surface from us in that case?