Try them with any other period, like 15 days which you used in your
initial
example.

Hi Fred,
Nice to see you back,
There you go .... a new pic with irregular dates,
http://www.fransysco.net/interest/in...ular_dates.gif

Theres a difference between the
ACCRINT function - and the -
ACCRINTM function.

ACCRINT requires intervals.
But I'm using ACCRINTM which has a maturity ( = settlement ?) date.
So there's an issue date and a settlement date, but no (other) periods.

Nth