PLACE OF NIGHT WORK IN INDUSTRY 15 
shifts regularly operated, a five-night per week program is 
used; in 29 plants the employees work for six nights; in three 
plants they work seven nights, and in one they work only 
four nights. Whereas in the rotating plan, 93 plants work 
seven or ten hours nightly and only five for a longer period, 
in the plants on a fixed regular night shift plan, 45 work 
seven and ten hours per night, and 35 call for from ten to 
thirteen hours of work each night. 
In the establishments where night work is carried on on 
a temporary fixed shift basis, the tendency toward intensive 
operation for a lesser number of nights is more marked. In 
this group, 40 out of 47 plants which submitted data on 
this subject to the Conference Board work five nights per 
week, six plants work six nights, and one plant works four 
nights per week. That a longer period of hours per night is 
worked than in the case of other forms of night work is shown 
by the fact that in 33 of the 36 plants reporting this item, the 
schedule of hours calls for ten to thirteen hours of work. In 
thirteen plants from seven to ten hours of night work is re- 
quired. 
The schedule of hours of work, classified according to plans 
of night work organization and by industry, is shown in 
Tables 3-6.