At 3:47 a.m., my daughter sat fully upright in bed, wide awake and ready to start the day. It was still dark outside our hotel room in Tokyo, but trying to explain time zones to a 4-year-old is futile.

I’ve never struggled with jet lag. I run on caffeine and enthusiasm until my circadian rhythm catches up, and within a day or two, I’ve adjusted. But a 16-hour time difference is a different problem with a preschooler in tow, one that’s hard to manage, let alone explain to someone whose body is telling them it’s noon even though the sky is dark.

We flew from California to Tokyo

We’d flown from San Diego to Tokyo, the first stop on a long trip…