This paper integrates the Time Dilation Gradient (TDG) concept into the SU(5) Grand Unified Theory (GUT) to address theoretical challenges such as proton decay predictions and gauge coupling unification. By introducing a time-dependent factor, Theta($t$), the modified SU(5) model aligns more closely with experimental data, extending the predicted proton lifetime and improving gauge coupling unification. This integration provides a more comprehensive understanding of how temporal variations influence particle interactions and field dynamics, enhancing the theoretical robustness and empirical viability of the SU(5) model.