<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED MARCH 20, 1998, TO THE
CLASS A AND CLASS B PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT SUPERSEDES AND REPLACES ANY EXISTING SUPPLEMENTS TO THE
PROSPECTUS. THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT
CONTAINED IN THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH
SUCH PROSPECTUS.
The cutoff time for receipt by the Portfolios of purchase and redemption orders
is the time of the calculation of NAV set forth below for each Portfolio.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
The NAV for the Treasury Portfolio, the Government Portfolio, and the Money
Market Portfolio is currently 4:30 p.m., Eastern Time, as described in the
current prospectus. It is anticipated that the time for determining the NAV for
the Treasury, Government, and Money Market Portfolios will be changed to 5:00
p.m., Eastern Time, in the near future. Shareholders will receive prior written
notification of this or any future change to the NAV calculation time.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
CMS-B-001-01
<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED MARCH 20, 1998, TO THE
CLASS C PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT SUPERSEDES AND REPLACES ANY EXISTING SUPPLEMENTS TO THE
PROSPECTUS. THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT
CONTAINED IN THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH
SUCH PROSPECTUS.
The cutoff time for receipt by the Portfolios of purchase and redemption orders
is the time of the calculation of NAV set forth above for each Portfolio.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
The NAV for the Treasury Portfolio, the Government Portfolio, and the Money
Market Portfolio is currently 4:30 p.m., Eastern Time, as described in the
current prospectus. It is anticipated that the time for determining the NAV for
the Treasury, Government, and Money Market Portfolios will be changed to 5:00
p.m., Eastern Time, in the near future. Shareholders will receive prior written
notification of the or any future change to the NAV calculation time.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
CMS-B-038-01
<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED MARCH 20, 1998, TO THE
SWEEP CLASS PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT SUPERSEDES AND REPLACES ANY EXISTING SUPPLEMENTS TO THE
PROSPECTUS. THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT
CONTAINED IN THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH
SUCH PROSPECTUS.
The cutoff time for receipt by the Portfolios of purchase and redemption orders
is the time of the calculation of NAV set forth above for each Portfolio.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
The NAV for the Treasury Portfolio, the Government Portfolio, and the Money
Market Portfolio is currently 4:30 p.m., Eastern Time, as described in the
current prospectus. It is anticipated that the time for determining the NAV for
the Treasury, Government, and Money Market Portfolios will be changed to 5:00
p.m., Eastern Time, in the near future. Shareholders will receive prior written
notification of this or any future change to the NAV calculation time.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
CMS-B-039-01
