Here's my experience:

We went hardcore on the sleep-training and it took. My daughter went to bed every night at 8pm. She woke up on her own at 7 am and napped for 1-1.5 hours starting anytime from noon to 1:30. That makes travelling difficult because we had to allot 2 hours in the middle of the day for nap and had to be back in the hotel by 8pm. When we went to LA, she didn't adjust to the time zones, so she would fall asleep at 5:30 pm and wake up at 4am. That trip made us cancel our trip to Korea. We weren't about to have her on a completely reversed am/pm shcedule, and on the off chance we could get her to adjust, we didn't want to spend that much money, travel that far to lose 2 hours every day to nap and be in our hotel by 8pm every night.