I am using XIRR to calculate the IRR on stock market investments. Outflows are the result of 1) buying shares and 2) paying broker fees. Inflows are the result of 1) Dividends and 2) selling shares. It works most of the times, but in a particular case, it fails and returns #NUM! (if called from VBA using application.run method, the function returns "Error 2036").

Cash flow data fed to XIRR is as follows :

Flows : ($6,138.49), $40.00, $4,817.98, $40.00, ($1,741.00), $1,712.00
Dates : 24-Aug-2000, 2-Oct-2000, 22-Dec-2000, 3-Jan-2001,4-Jun-2005, 5-Jun-2005

However, if I change the last date from 5-jun-2005 to 6-jun-2005, XIRR seems to work properly. Any clue anybody ?

Thanks in advance for support.