In this letter, nonuniform period time-modulated arrays (NTMAs) are investigated and analyzed in terms of radiated power at harmonics, and a more general and accurate closed-form expression is derived. Although there are some studies on the radiated power of NTMAs, it is claimed that the derived expressions in these studies have restrictions to be used as final forms. To overcome these restrictions, a new method is proposed and hence a closed-form power expression is achieved for uniform/nonuniform switching. Moreover, the obtained results are discussed over comparative examples to emphasize the differences among the recent findings. As a result, it is concluded that the proposed method is an effective solution that can eliminate the limitations of the studies in the literature.