  In the present work, we have reported $\beta^+$/EC-decay half-lives for $Z =
21 -30$ nuclei using large-scale shell-model. %and N $\leq$ A recent study
shows that some proton-rich nuclei in this region belong to the island of
inversion. We have performed calculations for these nuclei using KB3G effective
interaction, while for Ni, Cu, and Zn nuclei we have used JUN45 effective
interaction in the $f_{5/2}pg_{9/2}$ model space. The calculated quenching
factors for $fp$ and $f_{5/2}pg_{9/2}$ space using KB3G and JUN45 effective
interactions are also reported. Shell-model results of $\beta$-decay
half-lives, excitation energies, log$ft$ values, and branching fractions are
discussed and compared with the available experimental data. We have obtained a
reasonable agreement with the available data.
