The start date was published by the health ministry on Tuesday for the first time since the ban was announced last year, the China Daily reported, adding no penalties or enforcement details were released.
Beijing had committed to introducing the ban by January 9 when it signed the World Trade Organization (WHO) Framework Convention on Tobacco Control five years ago.
China missed the January deadline due to a lack of state-level legislation, ineffective administration, low-priced cigarettes and deep-rooted tobacco culture, the official Xinhua news agency reported in January.
A similar ban introduced in Shanghai before last year's World Expo has proved to be largely ineffective, with smokers continuing to light up openly in front of "no smoking" signs in hotels, restaurants and conference halls.
Tobacco is the country's top killer, and smoking and exposure to second-hand smoke result in a huge medical and social cost with more than 3.5 million Chinese likely to die from smoking related illnesses each year by 2030, according to a January report by Chinese and foreign medical experts.
Mainland China has more than 300 million smokers, WHO statistics show, and nearly 1.2 million Chinese people now die from smoking related diseases each year making up one fifth of the world total.