Planting time effect on genetic potential of wheat advanced lines for earliness and yield traits was studied through genotype-by-environment and heritability during 2012–2013 at The University of Agriculture, Peshawar, Pakistan. The breeding material comprising fifteen wheat genotypes including 12 advanced lines and three check cultivars. All the genotypes were grown under normal and late planting conditions in a randomized complete block design with three replications. According to analysis of variance, genotypes revealed significant (p≤0.01) differences for all the traits except days to maturity. For environments, highly significant differences were observed for majority of the traits; however, flag leaf area and 1000-grain weight were non-significant. Genotype × environment interactions were highly significant for days to heading, grains per spike and grain weight per spike while for grain yield it was merely significant (p≤0.05). Significance of wheat genotypes, environments and genotype by environment interaction authenticated that differences might be due to diverse genetic makeup of the genotypes and their interaction with environments. According to genetic variability, yield traits revealed low to high heritability (0.14 to 0.64) which provides reliability and more chances to the genotypes to be recognized by expression of their phenotypes and effective selection. On average, the grain yield of the genotypes was reduced by 20.14% due to late planting. Overall, genotype DIK-2 was found superior followed by lines DIK-1, NIFA-1 and NIFA-5 under normal planting. However, lines NIFA-1 and PS/CCRI-2 were the best performers with late planting. These lines could be further utilized for commercial cultivation as well as in future breeding programs to evolve new cultivars with good yield potential.