This research was undertaken to investigate 28 genotypes (21 F₁-crosses and their seven parents) for heading date, plant height, 100-grain weight, and grain yield plant^-1under two planting dates (November 21^st as regular planting date and 21^st of December as late planting date) at El-Mattana, Agricultural Research Station, Luxor governorate, ARC, in2017/2018 and 2018/2019 growing seasons. Highly significant differences among genotypes, parents, crosses, and parents vs. crosses for all traits investigated under both sowing dates. Heat stress reduced estimates of all studied traits. Three parents (P₁, P_6,and P₇) and seven F₁-hybrids (P₁ × P₂, P₁ × P₃, P₁ × P₅, P₁ × P₇, P₄× P₇, P₅ × P₆,  and P₆ × P₇)  were highly tolerant, less susceptible (heat susceptibility index less than one), and less sensitive (less than one) for heat stress. Mean squares due to general (GCA) and specific (SCA) combining ability were highly significant for all studied traits. GCA/SCA ratios' magnitude were lower than one for all studied traits under both planting dates. The parents P₅ and P₇ were having significant adverse GCA effects for heading date, and the parents P₂ and P₄ showed significant positive effects for plant height and grain yield. The hybrid P₂ × P₇ observed significant positive heterosis in grain yield, 100-grain weight, and plant height, however, significantly negative in heading date in addition to satisfactory performance.