The exact date was April 26, 2001.
"[Since] "the Hire" debuted in 2001 there have been several companies
to go on-line with short films. . . .
"Seven months after premiering April 26 on www.BMWfilms.com, the films
have appeared on Independent Film Channel and Bravo. The films have
been downloaded more than 10 million times, according to BMW, and the
shorts themselves were widely praised, receiving broad attention from
the general press."
Evergreen State College:BMW: The Hire Campaign
Confirming sources include, among many others:
"To considerable fanfare, in April 2001 BMW of North America launched
a site prosaically named BMWFilms.com featuring an ongoing series of
short films under the rubric The Hire."
A List Apart: All The Access Money Can Buy
"The films ("The Hire") were released online from April 2001 through
2002, BMW's best sales year to date despite the terrorist attacks of
Sept. 11, 2001."
Hollywood Reporter, 9/16/03
I found the year with the following Google search:
"bmw films" launched
I found the month and then some other confirming sources with the
following two searched:
"bmw films" launched 2001
"bmw films" april 2001
I am confident that this is exactly the information you are seeking,
and I am glad to be able to get it for you promptly. If anything is
unclear, please ask for clarification before rating the answer.