Re: three questions about //e

[dempson@actrix.gen.nz (David Empson)]

Linards Ticmanis <ticmanis@coli.uni-sb.de> wrote:

> David Empson wrote:
> 
> [OS "lowest" dates]
> 
> > > That would be odd, as most OS manufacturers chose 1 January of the
> > > year they started implementing.
> > 
> > The Mac uses 1904 or 1956, depending on the machine.  (The system
> > software always maps this as if the start date was 1904.)
> 
> Is there any reason for these particular years?

They are both leap years, which makes some calculations easier.  In
addition, 1900 is _not_ a leap year while 2000 is (and 2100 is not), so
1904 is the first leap year in an unbroken sequence for the next 192
years, which completely spans the 32-bit second counter (a period of
about 136 years).

1956 is rumoured to be the year of birth of one of the people who worked
on the Mac hardware, if I remember right.  It also has leap years every
four years for at least 136 years (the same would not be true if the
start date was 1964 or later).