The employer does not have the ability under USERRA to deny your request for leave. You are only required to give your employer notice, not to obtain permission. Your employer has no right to veto the timing, frequency, duration, or any other aspect of leave, and cannot require you to rearrange your schedule or find a replacement. If the timing is a problem, your employer may wish to contact your Commanding Officer. It is Department of Defense (DOD) policy that the Commanding Officer should work with employers to resolve scheduling conflicts. The Commanding Officer will accede to the employer's reasonable request to reschedule military training, unless doing so would detract from unit readiness and mission accomplishment. Rescheduling must be kept to a minimum. National Guard and Reserve units train together, and they must go to war together. The training periods are scheduled so that the unit can be trained together. If an individual unit member undergoes training at a different time, it is likely to be impossible to replicate the training that the rest of the unit received. As a result, the individual unit member may not be able to perform some critical task, resulting in additional casualties and endangering the accomplishment of the mission.