I’ve discovered that StreamInsight holds the key to eternal “youth”!
var newLifeStream = from e in lifeStream
//Events greater than 39 years ago get moved forward a yeare => e.StartTime.AddYears(39) >= DateTime.Now ? e.StartTime.AddYears(1) : e.StartTime,
e => e.EndTime - e.StartTime )
It may need a little tweaking, particularly the event duration, but I still have two and a half months before “go-live.”