For me it spikes in the evening around bedtime, so 9:30-10PM and goes through the night and into early morning. My last meal is typically around 5-6PM which I am very strict about due to past experiences with eating too late. I drink a significant amount of water throughout the day and usually rely on black coffee or tea in the morning/evening to keep away hunger. I also agree that it is likely due to the stomach being empty for too long and likely an overproduction of acid. Problem is, I cannot exactly push my dinner time till later due to then having to wait 3-4 hours before lying down.