The peak hours in Btc trading really differ or change a lot because it really depends on your daily volume, although there is a specific time and that is when the Asian market opens, usually there is a slight rise that if you take a look at the graphics btc history in an hour you can notice very accurately.
Now, the peak hours as I said vary a lot in bitcoin, it is not very essential to try to look for exact moments, just to understand when the transactional volume increases consistently.
Keep in mind that you place that with your analysis.