By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date. Can the traveler choose whether or not to use the per diem rate?He submitted claims for per diem and miscellaneous travel expenses while in a TDY status from Janu- ary 12 through February 11, 1978. Such leave shall not be cumulative from fiscal year to fiscal year. United States when holding court away from their homes. United States when holding court away from their homes. 8 program occurred in the 1980s and 1990s . Per Diem Dispatchers.