From non-federal site:
Transition PTDY may be used in increments (not to exceed days authorized); may be taken in a series of trips in conjunction with transition leave (must have a duty day between transition leave and PTDY); or maybe taken in its entirety in conjunction with transition leave (e.g. Soldier elects to take transition PTDY, with full 20/30 days as one trip; starting transition leave on the next day).
From Army HRC:
Are all Soldiers authorized Permissive Temporary Duty (PTDY) at transition?
A5: No. Only active duty Soldiers retiring or involuntarily separating from military service are eligible for transition PTDY. It is not authorized to Soldiers who complete their time in service and ETS and is not authorized to officers resigning from active duty (REFRAD). It is not authorized to Soldiers who choose not to reenlist during their reenlistment window, and are later ineligible for continued service. It is an authorization, not an entitlement. PTDY is not appropriate, and is not authorized, to Soldiers who remain in the same residence and have already found post-military employment. Soldiers must have a need to either relocate or to conduct job search activities during the dates requested for transition PTDY.
Can Transition PTDY be taken in combination with ordinary leave?
A7: Yes, Soldiers taking the entire transition PTDY period as one absence may be granted transition (ordinary) leave without a duty day between the two periods of absence. For example: A Soldier completes final out and then uses transition PTDY as one trip and starts transition leave on the next day. There is no requirement to complete a duty day between the periods of absence, if they occur after final out. However, the Soldier must complete all out-processing and other transition requirements, including final out with Personnel and Finance, before departure on transition PTDY and leave. Passes, including weekend passes, cannot be granted after final out. Soldiers cannot be granted transition PTDY in increments after final out from their permanent duty station.
[This appears to indicate PTDY first with no requirement to return to the home station. RG]
Ron