Hello,   I am a novice to intermediate user and not super great with dates in SAS. I have a dataset where we have gestational age of an infant in weeks such as 38.20 and the infants date of birth. Essentially I need to figure out from DOB backwards using gestational age to determine a sort of proxy for the entire time period of pregnancy. I need to have a list of each day of pregnancy by date, this is to determine sort of a window of time where they could have an adverse exposure during pregnancy. This found date range will be used to inform if an exposure by specific dates occurred during the course of their pregnancy.   Like I said, I am not great with SAS dates and am a bit rusty and not sure where to start. I have been trying to google things but it is not giving me what I need because I am trying to find the best words to describe what I am attempting to do. Please let me know I would greatly appreciate anyone's help! Thanks! ... View more