Chapter 3, Part E of the Joint Travel Regulations (JTR), titled “Leave in Conjunction with TDY,” establishes the rules and financial limitations for combining personal leave with official Temporary Duty (TDY) travel. The regulation permits travelers to combine leave with official travel provided it incurs no additional cost to the Government, with reimbursement strictly capped at the constructed cost of the official travel had no personal leave occurred. It outlines specific allowances for complex scenarios, such as receiving TDY orders while already on leave, interrupting leave for official duties, or being recalled from leave due to operational emergencies. The chapter dictates the effect of leave on per diem, stipulating that Service members receive no per diem for days in a leave status, while detailing specific per diem computation rules for civilian employees taking leave around non-workdays. Furthermore, it provides comprehensive procedures for handling personal emergencies while on TDY, authorizing limited travel and transportation allowances for personnel who must interrupt their mission to return home or travel to an alternate emergency location. Finally, the regulation governs specialized administrative situations, including calculating daily rates for long-term lodging when leave is taken, reimbursing members whose ship relocates during an authorized absence, and covering retained TDY lodging expenses for Service members who take leave to visit evacuated dependents at a safe haven.