After struggling for two months with a peculiar data set received from an
opposing 'expert' in Texas, I have finally reached the hypothesis that the
data was constructed by cutting and pasting between two Excel files, one
originating from an Apple Mac using the 1904 date system and the other from
a PC using the 1900 date system. The consequence is that half the dates in
the consolidated file are back-dated by four years and a day, which in turn
led to some bizarre analysis and conclusions.
One can imagine the mischief that could result from a few inadvertent cuts
and pastes in a range of activities from conducting drug trials to
constructing actuarial tables. "Hey, lookee here! This group of geezers over
here lived four years longer than that group of geezers over there (error
caused by pasting birth dates to a PC file from a Mac)."
The anomaly is documented by Microsoft but I am curious to know how many
users of excel who occasionally or often exchange files with colleagues who
may or may not be using the same system are unaware of it?
Tom Walker
Bowen Island, BC
604 947 2213
