It's difficulty to choose a especific time, you will play against people from all the Earth, there are some questions to think before choose a specific time, like what country are able to play, the number of available games, average buyin, and your timezone, although can have more weak players in some specific time, you can get in a table only with good players, you can't choose a table in a tournament, so you will need luck to get involved only with weak players, or at least with more weak than good players on your table.