Actually, it would be more suitable if you say it with people whom you would expect to meet more frequently, like friends or colleagues or gym buddies 
For passer-by, like shop clerks, “konnichiwa” is fine enough.
Actually, it would be more suitable if you say it with people whom you would expect to meet more frequently, like friends or colleagues or gym buddies For passer-by, like shop clerks, “konnichiwa” is fine enough.