Time Difference in LongForm Data

[hatemamer]

I have a long form data set. cn is case number. Each case can have multiple procedureID each procedureID is on a different procedureDate. I am trying to create a new variable timetonxt which is the days from one procdureDate to the next for each cn (case number).

[Clyde Schechter]

by cn (procedureDate), sort: gen timetonxt = procedureDate[_n+1] - procedureDate