Hi

The MOD() function is dividing the number of days between Today() and your
date in B1, by 91 (approximate number of days in 3 months) and returning the
remainder.

The =0 and <= 5 is comparing this values and if it is equal to or more than
0, and les than or equal to 5, then show DUE Date, otherwise show nothing.

The response from David using Datedif gives an exact result.

--
Regards
Roger Govier

"kyoshirou" wrote in message
...
=IF(AND(MOD(TODAY()-B1,91)=0,MOD(TODAY()-B1,91)<=5),"DUE DATE","")
what does that =0 and <=5 means?



"Roger Govier" wrote:

Hi

This not exact, but probably close enough for your requirement
=IF(AND(MOD(TODAY()-B1,91)=0,MOD(TODAY()-B1,91)<=5),"DUE DATE","")

--
Regards
Roger Govier

"kyoshirou" wrote in message
...
For example, if i have a date field of 28/02/08 in column B,
can i configure in column C such that every 3 months, message like:
date
due
is up" automatically. Then after 1 week or few days ( 3 or 5), that
message
will auto-erase.
And after 3 months, the message "date due is up" will output again
auto?


Thanks!