Property offset : Iv3IVL; (Read/Write)
An interval of elapsed time (duration, not absolute point in time) that marks the offsets for the beginning, width and end of the EIVL measured from the time each such event actually occurred.
Example: if the specification is "one hour before breakfast for 10 minutes", code is CM, IVL.low of offset is -1 h and the IVL.high of offset is -50 min.
The offset SHALL be null if the event code specifies "before", "after" or "between meals". The offset SHALL be nonNull if the EIVL is nonNull and the event code is C, CM, CD, or CV. The offset may or may not be null for the event codes HS and WAKE.