Hi Barry,
Requirements for population of Study Days in addition to Date/Time variables are from FDA rather than from CDISC SDTM IG.
See recent FDA’s “STUDY DATA TECHNICAL CONFORMANCE GUIDE”
http://www.fda.gov/downloads/ForIndustry/DataStandards/StudyDataStandards/UCM384744.pdf
On page 9:
". Whenever --DTC, --STDTC or --ENDTC are included, the matching Study Day variables (–DY, --STDY, or—ENDY, respectively) should be included. For example, in most Findings domains, --DTC is Expected, which means that --DY
should also be included. In the Subject Elements domain, SESTDTC is Required and SEENDTC is Expected; therefore, both SESTDY and SEENDY should be included."
Kind Regards,
Sergiy