Interesting question... any particular reason for you to be interested in this 'cohort'?
I fell ill on 1.1.1979, between 14.00 and 15.00 hours, while cycling with my common law wife in the Dutch polders, while it was freezing very hard and had snowed a lot.
I decided to cycle home as fast as I could since I was collapsing and couldn't afford to do so while it was so very cold. I can still recall the - for me - browngrey sky, that seemed to collapse.
My wife fell ill 9 days later: EBV. We separated 6 years later, and had then been both ill then for 6 years, with all the symptoms found later in the CDC-definition, though it differed some for her and me.