Every sommer we travel to Denmark and back again to the US. There is a six hour difference in time zone. I have taken Requip for the last five years, adding sinemet just last year.
I keep my watch set on the time of the country I have just left. From the US, when we lose 6 hours, i skip the morning dosis, set my watch at local time at lunch, take the lunch dosis, and I'm on local schedule. With eight hours difference you may want to take early lunch and dinner for a couple of days when you just arrive.
On the way back, when we gain six hours, I do end up with one day that contains four meals and four dosis of meds. But I go to bed early, and for the next few days I will usually wake up at 4 or 5, but I try to wait until at least 6 if I can, before I take my morning dosis. I am usually quite badly jet lagged both ways, but only for a day or two.

Be sure to request assistance in both airports when you book. Even though your husband may object to being wheeled in a wheel chair - it's early days for him, and he may still be too proud, as was I. But with a wheel chair you will avoid the lines at security, and you will be seated first in the plane - no rush, no pushing.

Requip has now and then caused me to faint during long flights. It is an awful feeling of disappearing and turning deaf and mute. Your husband should be prepared for the possibility, though it is unlikely. As soon as I begin to hear ringing in my ears, I alert my husband, and when he keeps speaking to me, and keeps stroking my hands, I avoid losing consciousness.

Requip can also affect one's feet. If your husband suddenly feels that his feet are not cooperating, a .50 mg reduction in one of the daily dosis may help bring his feet back to 'normal'.

This is more advice than you asked for, but who knows.... it's good to be prepared.
Have a wonderful trip.

birte