In the previously published papers the authors made an attempt to develop a possible model of Black hole cosmology in a constructive way. In this model, forever rotating at light speed, high temperature and high angular velocity small sized primordial cosmic black hole of mass $\frac{e^2}{4 \pi \epsilon_0 G}$ gradually transforms into a low temperature and low angular velocity large sized massive primordial cosmic black hole. At any time $H_t$ represents the angular velocity. At its ending stage of expansion, for the whole cosmic black hole as practically remains constant, its corresponding thermal energy density will be ‘the same’ throughout its volume. This ‘sameness’ may be the reason for the observed ‘isotropic’ nature of the current CMB radiation. Observed cosmic red shift can be re-interpreted as an index of cosmological galactic atomic light emission phenomenon. Validity of this model can be well confirmed from the combined study of cosmological and microscopic physical phenomena. Finally it can be suggested that, the cosmological time is real and absolute. By interconnecting the present cosmic time with the present CMBR energy density the authors made an attempt to fit and estimate the current cosmic age and its obtained magnitude is close to 282 trillion years.