© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Deutschland, part of Springer Nature.Day length is an important environmental factor in the lif cycle of plants. If the plants do not receive an optimum day length for the appropriate amount of photosynthesis, they lose their ability to achieve their best yield potential under various types of stress. Therefore, adjusting the sowing date is an easy and low-cost strategy to overcome the negative effects of stresses. The study aimed to evaluate the influence of sowing dates on the yield and yield components of three exotic white mustard genotypes. The experiment was arranged in a split plots in randomized complete blocks design with three replications during 2020 and 2021 under hot humid continental—Dsa type climate of Ankara, Turkiye. Four sowing dates separated by a delay of 15 days (starting from March 15 to May 1) were used in the main plots and three genotypes (Sr1, Sr2, and Su) were used in the sub-plots. The result showed significant differences in yield parameters of number of branches plant−1, seed yield, and fixed oil yield, between years. The results also showed a significant genotype × sowing dates interaction. The maximum seed yield of 1084 kg ha−1 was detected from the 15 March sowing in Sr2 while the lowest seed yield of 141 kg ha−1 was determined on the 1 May sown plants in Sr1 during both years. The genotypes had synchronization towards flowering in the month of May and June with 11 h 6 min to 12 h 5 min day length. Principal component analysis showed genotypes × sowing dates significant interactions for seed yield, fixed oil percentage and fixed oil yield. The major fatty acid among all genotypes was oleic acid acid, which demonstrated a negative correlation with eicosenoic (−0.93**) and erucic fatty (−0.99**) acids. It was indicated that Sinapis alba sown in March was preferable compared to other sowing dates to achieve higher yield and quality; Sr2 was recommended for further evaluation in energy sector.