Randomly sample timestamps during works hours of a fixed time period

I would like to randomly sample timestamps that fall inside the working hours (09:00-18:00) of the workdays (Mo-Fr or maybe Su-Th...) for a given time period (e.g. a month). What would be the most elegant way to do it?

It seems like pandas.bdate_range(t1,t2) can easily yield the workdays (is this notion configurable?). But What about the work hours?