Thank you for your help in this problem. I would like to code for week to denote which week in the trial the participant is in. Because the goals incrementally increase week by week, I'd like to have this variable so I can assess for variation across weeks in the study. I am not concerned with calendar weeks, but care that week 1= days 1 through 7, week 2 = days 8 through 14, etc. There might be days when no data was present, so the date is missing. I'd like the "want" dataset to code the week and day for those missing dates, so it reflects continuous participation and missing data. I hope this is more clear and very much appreciate your expertise in advance.   Thanks, Stephanie       ... View more