Peanut (Arachis hypogea L.) is an important nut crop extensively grown in rainfed regions of Pakistan. The crop requires low inputs; thus, could grow successfully under diverse environmental conditions. Due to pegging ability, peanut grows aggressively in sandy and sandy-loam soils. However, it has not introduced to Thal region of southern Punjab, Pakistan. A two-year field experiment was conducted to optimize sowing dates for two peanut genotypes ('BARI-2016' and 'NO-334') in Thal region (Layyah). Similarly, a yield trial was conducted at Chakwal where both genotypes are extensively grown. Five sowing dates (10th April, 1st May, 20th May, 10th June and 30th June) were included in the study. The highest seed yield was obtained with early sown crop (10th April) during both years. Pod formation reduced with increasing atmospheric temperature and no pods were formed on the plants sown on 30th June. Decreased pod formation seemed a major reason for low yield in late-sown crop. The highest yield was observed for the crop sown on 10th April, which was decreased by 40% for the crop sown on 1st May. Genotype 'BARI-2016' performed better for seed yield at both locations compared with 'NO-334'. The results suggested that genotype 'BARI-2016' is more adaptive to arid and semi-arid condition under rainfed or irrigated conditions. Sowing peanut at optimum time would increase seed yield in arid and semi-arid regions. Nonetheless, 'BARI-2016' can be grown under rainfed and irrigated conditions successfully.