Regarding past practice on the switch in calendars, one piece of evidence
is provided by the Glasgow edition of the Correspondence of Adam Smith. In
their preface and any general notes, no mention is made of the calendar
switch. However, two of Adam Smith's letters published in this volume do
seem to acknowledge the difference in calendars.

The first is letter #7 in the collection and was dated by Adam Smith
himself as from Edinburgh, 4 Feb.1748/9.  It was written to Theophilus
Leigh at Baliol College, Oxford and in it, Smith resigns his position as
Snell exhibitioner at Baliol.  A note by the editors to this letter
suggests that Smith dated it 1748/9 because he was sending it from
Scotland which since 1600 had been using the New Style practice of
beginning the year on 1 January while England was still using the Old
Style practice of beginning the year
on 25 March.

The other is letter # 11 and was dated by Smith as from Glasgow,
19 Jan.1752 N.S.  There is no note by the editors or any other explanation
of the meaning of N.S. I presume it stands for New Style. This letter is
to James Oswald and as best I can tell Oswald was based in London at the
time, not in Scotland; so again Smith is apparently sending the letter
from Scotland to England and this around the time when England would have
shifted to the same practice as Scotland.  Letter #12
is from David Hume to Smith and is dated 24 Sept. 1752  (no use is made of
N.S.). Possibly both Hume and Smith were in Scotland when Hume's letter
would have been sent.  A quick browse through some of the following
letters also did not indicate any use of N.S.

I am not advising Tim Geitner on the bank bailout or Tom Daschle on his
tax returns so I had the time to look into this. After this thread, I am
now expecting sometime down the road one of my students will turn in a
term paper 11 to 13 days late on the grounds that they thought I was using
Old Style practice in listing due dates on my syllabus.

David Mitch