Optimistically – Memorial Day. Realistically – Late June / Early July
China implemented draconian lockdown measures whereby citizens couldn’t even leave their homes (China installs door monitors to alert authorities when people try to leave their home). Even after nearly 3 months of these draconian measures China has yet to lift its lockdown of Wuhan Province and will likely only do so sometime next month. In contrast, the U.S. and western countries have implemented much less drastic measures with little enforcement.
If our less intensive measures were to somehow miraculously be as effective as China’s hardline measures then we’d be looking at Memorial Day with regard to lifting lockdowns. However, it follows logically that our efforts won’t be as effective as China’s which would mean that we’d be in lockdown for longer than them.