Six bread wheat genotypes were crossed in half diallel model during 2021/2022 season, to determine the mean performance. Parent and their F1 were evaluated using a randomized complete block design (RCBD) with 3 replications under normal and late sowing dates in the 2022/2023 season on the research farm of the agronomy division, faculty of agriculture, Mansoura University, Dakahlia Governorate, Egypt. Data were taken on the earliness and morpho-physiological traits. Results revealed that the variance of sowing dates was significant or highly significant for all studied traits except for total chlorophyll content. The sowing date × genotypes interactions were found to be significant for all traits except for grain filling rate. Each additive (D) and dominance (H1 and H2) gene effects were significant for most traits under each sowing date except additive gene effects for days to heading, days to maturity under late sowing date and chlorophyll content under normal sowing date, dominance gene effects for days to maturity, grain filling period, grain filling rate, under late sowing date and chlorophyll content under normal sowing date due (H1 and H2) and (H1) for flag leaf area under normal sowing date. All the traits were given large values for heritability in the narrow sense (h2(n.s)) under each sowing date, except days to heading under late sowing date, days to maturity, flag leaf area and chlorophyll content under normal sowing date which had low values of heritability in narrow sense.