“Time-based” workplace smoking bans during working hours (including and excluding lunchtime) and combustible cigarette and heated tobacco product use: a cross-sectional analysis of the 2020 JASTIS study

•In some private companies, “time-based” workplace policies which ban smoking during working hours (including or excluding lunchtime) have been implemented.•Little is known about the relationship between time-based smoke-free policies for working hours and combustible cigarette and HTP use. In this study, we focused on workplace bans on smoking during working hours including or excluding lunchtime.•Bans on smoking during working hours which include lunchtime may be successful in reducing use of combustible cigarettes and HTPs, but allowing their use during lunchtime may reduce the effectiveness of the ban. Not only place-based, but also time-based smoke-free policies are important for tobacco control in the workplace.