Section 1340.6 - Assignment of observation times(a)Daylight hours. All daylight hours between 7 a.m. and 6 p.m. for all days of the week shall be eligible for inclusion in the sample.(b)Random assignment. Except as provided in paragraph (c) of this section, the day-of the week and time-of-the-day shall be randomly assigned to observation sites.(c)Grouping of observation sites in close geographic proximity. Observations sites in close geographic proximity may be grouped to reduce data collection burdens if: (1) The first assignment of an observation site within the group is randomly selected; and(2) The assignment of other observations sites within the group is made in a manner that promotes administrative efficiency and timely completion of the survey.