When is the mandatory date for wearing male and female E1-E6 service dress white with blue piping?

The mandatory date for wearing the male and female E1-E6 service dress white with blue piping is indeed October 31, 2021. This date marks when the transition to this specific uniform became a requirement for service members. The implementation date is crucial because it ensures uniformity and adherence to updated dress codes within the military, reflecting changes in regulation and the modernization of uniforms as well as addressing service member needs for comfort and aesthetic appeal.

Given the context of the options available, the selection of October 31, 2021, aligns perfectly with these updates in uniform standards, making it the correct and most relevant date for this requirement. This date serves as the official benchmark for service members to maintain compliance with uniformity standards as per the guidelines issued by military leadership.