My third full day in Japan began with walking Toma at 5:30AM in what became a heavy rain. He had woke me again at 4AM JST, same as the night before, hungry and wanting to be feed. I gave him some dry food and struggled to go back to sleep. It was then that I finally realized the source of the problem–Toma was suffering from jet lag! In fact, 4AM JST equated to 5PM EST, his regular feeding time in the USA. Despite travelling the many hours and over 6000 miles, his day by day regimen remained in accordance with his circadian rhythm.
Since I do not suffer much from jet lag, I failed to realize how Toma had been affected by his travel experience. Doing some quick research I learned that his sleep patterns are influenced by way of daylight and nighttime hours and that his feeding routine was also consistent with a particular point of day. Thus, the disruption to that regimen explained his middle of the night behavior.
I began to modify his feeding to help with the transition and establish a routine. He appears to have responded quickly to our new routine. Last night, we both slept soundly until waking up at our regular 5:30AM time!