Hi! I would agree with the other professionals who have commented on this answer that there is no real "best time", but typically employers hire for rising juniors and seniors. The reason for this is because they've typically narrowed down their career path and have taken certain courses. Hiring upperclassmen also allows employers to truly assess whether or not they'd be a good fit for the job/company upon graduation. That being said, if you feel you fit the qualifications I would encourage you to still apply and see what happens, it's never too early to get experience!