Calculating Per Diem for Trip that was Cancelled WHILE Traveling, 12+ Hours, No Lodging

Hello, I'm a DoD contractor and I had a question regarding per diem.

Back story:
My company sent me on travel from Norfolk, VA to Singapore. While flying, my company notified me that the remainder of the trip had been officially cancelled by the government liaison. When I arrived at the next airport, I spent several hours trying to get my luggage to take with me, but it was delayed. I ended up leaving the airport and driving back home. I ended up arriving back home on the same day that I left, but I spent about 15 hours traveling altogether.

Normally on the first travel day, I would receive 75% per diem for the destination location where I would be lodging at, which in this case would have been Singapore. However, since I never made it to Singapore, or lodged anywhere for that matter, I'm not sure what location they would use for the per diem rate.

In working with the military, my company bases a lot of their policies off of the Joint Travel Regulations (JTR). I'm looking through the JTR at "https://media.defense.gov/2022/jan/04/2002917147/-1/-1/0/jtr.pdf" which was recently updated on March 1, 2026. They don't clearly state how per diem is calculated during travel when it is cancelled for official reasons.

The only information I can find is in section "020309. Trip Length As It Affects Per Diem" (page 2-45). It states that:
"When travel is…more than 12 hours but less than 24 hours and no lodging is required" then "The per diem rate is based on…the highest locality rate for each day."
"Computation = 75% of the highest M&IE rate for each calendar day in a travel status."

Question:
What does the highest locality rate refer to?
A) My original and ultimate destination, Singapore
B) The airport I landed in after I received the cancelled trip notification
C) My primary residence, Norfolk
D) None of the above (sucks to suck)

I appreciate anyone that can lend assistance to this conundrum.