A tour of active duty for reserve personnel authorised from military and reserve personnel appropriations for work on active or reserve component programs. This includes annual screening, training camp operations, training ship operations, and unit conversion to new weapon systems when such duties are essential. Active duty for special work may also be authorised to support study groups, training sites and exercises, short-term projects, and doing administrative or support functions. By policy, active duty for special work tours are normally limited to 179 days or less in one fiscal year. Tours exceeding 180 days are accountable against active duty end strength.