No. The 90 days belong to you, not the employer. If you are anxious to get back on the payroll as quickly as possible, you should submit your application for reemployment right away. If you need time to readjust to civilian life, you should wait to submit your application. Once you apply, you are in effect saying that you are ready, willing, and able to return to work. Do not submit the application until that is the case, unless your reporting deadline is expiring.