Best time is not same for everyone. Probably best time is not depends from us at all, it depends from market.
I guess it can just be easier to get into trading, like it was with bitcoin few years ago, buy low and sell now when it's high. And opposite is when it's not so easy to trade. I think not all traders are earning money, it's not easy thing like most people imagine. Don't get into trading without knowledge. Learn about it, read here what other people say and then try something.