PR_OWNER_APPT_ID values

[dev]

I'm following the instructions in the MS-OXOCAL document to create a
meeting request. One of the fields to populate is
PidTagOwnerAppointmentId / PR_OWNER_APPT_ID. The document defines
this value as "the number of minutes between the start time and
midnight, January 1, 1601". For messages created now, in March 2010,
that would give values in the order of 215203440. However, using
OutlookSpy, I can see that messages created manually within Outlook
have values more like 1900099546, around 9 times more.

The example in MS-OXOCAL is from 26 Feb 2008 and has the value
1301555160. Now if you follow the document's own definition, that
would put the message somewhere around the year 4000. Or, if it
matches Outlook, it gives a difference of 598544386 in two years,
which works out to about 10 a second, which means that it starting
counting 6.34 years ago.

Can anyone explain what is going on ? Or is my maths just
screwy ?

- Tim Dale, BRE