  We revisit the epoch of cosmic speed-up characterized by the redshift of
transition from a decelerated to an accelerated phase. This redshift is termed
the transition redshift ($z_t$). We use the spatially Flat and Non-Flat
variants of the most common $\Lambda$CDM and XCDM models to put constraints on
the transition redshift along with the other model parameters. The data for
this analysis comes from the recent and updated Pantheon+ Supernova dataset and
the Hubble parameter measurements obtained from Cosmic Chronometers. We
consider both datasets with their respective covariance matrices incorporating
all kinds of statistical and systematic uncertainties. We observe that using
the combined datasets of H(z) and SNe, the best fit value of transition
redshift lies in the range $0.61 < z_t < 0.82$ for all four dark energy models.
Incidentally, we observe a positive curvature for the Non-Flat models and
correlations between several model parameters.
