I am trying to randomly select a survey schedule that includes both weekend days and two consecutive weekdays over a 34 week period.  I have created a data set that has all combinations of the variables (example below) with a total of 532 possibilities:    Obs    RESERVOIR    week    day     section        start                                    1        1          1     MON        1       Start Site - 1                                    2        1          1     MON        2       Start Site - 1                                    3        1          1     MON        1       Start Site - 2                                    4        1          1     MON        2       Start Site - 2                                    5        1          1     TUES       1       Start Site - 1                                    6        1          1     TUES       2       Start Site - 1                                    7        1          1     TUES       1       Start Site - 2                                    8        1          1     TUES       2       Start Site - 2                                    9        1          1     WED        1       Start Site - 1                                   10        1          1     WED        2       Start Site - 1                                   11        1          1     WED        1       Start Site - 2                                   12        1          1     WED        2       Start Site - 2                                   13        1          1     THUR       1       Start Site - 1                                   14        1          1     THUR       2       Start Site - 1                                   15        1          1     THUR       1       Start Site - 2                                   16        1          1     THUR       2       Start Site - 2                                   17        1          2     MON        1       Start Site - 1                                   18        1          2     MON        2       Start Site - 1                                   19        1          2     MON        1       Start Site - 2                                   20        1          2     MON        2       Start Site - 2                                   21        1          2     TUES       1       Start Site - 1                                   22        1          2     TUES       2       Start Site - 1                                   23        1          2     TUES       1       Start Site - 2                                   24        1          2     TUES       2       Start Site - 2                                   25        1          2     WED        1       Start Site - 1                                   26        1          2     WED        2       Start Site - 1                                   27        1          2     WED        1       Start Site - 2                                   28        1          2     WED        2       Start Site - 2                                   29        1          2     THUR       1       Start Site - 1                                   30        1          2     THUR       2       Start Site - 1                                   31        1          2     THUR       1       Start Site - 2                                   32        1          2     THUR       2       Start Site - 2   For this section i am only dealing with the weekdays portion, but so far i have the following SAS program:   PROC SURVEYSELECT DATA=weekdays METHOD=SRS n=2 OUT=weekdaysa noprint;     STRATA week day; RUN;   This does select 2 days per week but sometimes selects the same day for the week.  I would like the days to be consecutive (e.g., if monday is selected, then Tuesday would also be selected).   Thanks for any assistance.     ... View more