I take it around 2 or 3pm after having lunch because that's when I eat the most. It's just really important that you eat enough before taking it so if you eat most in the morning take it then, if it's around lunch time that's ok too. 6pm would be ok, but I don't think it's smart to take it right before going to sleep
just know that you have to eat enough or you could throw up as some people do. Hope this helps :)