"Jamie Collins" wrote
From testing I've conluded that seems Jet 4.0 gives entirely
consistent results using ISO-8601 standard date format, being
yyyy-mm-dd e.g. in VBA:

I should qualify my comment in saying it springs from VBA Excel and the date
formats of "yyyy.mm.dd" which I generally consider as European (esp with the
period sep char) and Asian (well mainland China at least), "mm/dd/yyyy" as
North American and "dd/mm/yyyy" for Commonwealth countries (generally).
When parsing string typed inputs some functions like Isdate() give kooky
results and then assigning the value to a spreadsheet cell without care can
lead to some unexpected casting/conversion. Once a genuine date datatype is
in use then things happen as you would expect.

However, for peace of mind using an unambiguous date format can be good
e.g.

strStartDate = Format$(datStartDate, "dd mmm yyyy")

I agree 100% - especially when crossing over to different vendors products!

Cheers Frank.