What is 'time' in FRW metric ?

[Widdekind]

In flat spacetime, differential distances & times are measured within the spacetime fabric. In the Schwarzschild spacetime, differential radial distances can be defined within the spacetime fabric, from [math]r \equiv circumference / 2 \pi[/math]. What about 'time', in the FRW cosmology solutions? Is 'time' measured fully within the spacetime fabric, so that the time is the 'integrated length' measured along the hyper-surface of spacetime? Or, is 'time' an 'absolute coordinate', measured along the 'vertical hyperspatial axis' of a closed cosmic spacetime??

 

Edited February 26, 2011 by Widdekind