Not very sure, but here goes one try ..

Assume you have in A1:E1,
the "1st of month" dates formatted as "mmm-yy", viz.:
Jan-05 Feb-05 Mar-05 Apr-05 May-05

And you have *dates* in 3 cols to the right,
i.e. in cols F to H from row2 down, e.g.:

02-Mar-05 12-Apr-05 21-May-05
11-Jan-05 01-Feb-05 31-Mar-05
etc

Put in the formula bar for A2 and array-enter (i.e. press CTRL+SHIFT+ENTER):

=IF($F2:$H2="","",--($F2:$H2<=A$1))

Copy A2 across to E2, fill down as required

--
Rgds
Max
xl 97
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GMT+8, 1° 22' N 103° 45' E
xdemechanik <atyahoo<dotcom
----
"Ruthki" wrote in
message ...

When I posted the question some of the formating may have made my
question unclear.

the columns with the array forumla in (eg {0,1,1) should be headed at
the top by the current month. (the headings have slipped over to the
right in the formatting.
---
I would like to create an array formula (in order to use the result to
multiply other arrays) to populate a table as below with the answers as
below (eg {0,1,1})


jan05 feb05
mar05 apr05 may05
mar 05 feb05 apr05 {0,0,0} {0,1,0} {1,1,0}
{1,1,1} {1,1,1}
apr 05 feb05 jan05 {0,0,1} {0,1,1} {0,1,1}
{1,1,1} {1,1,1}


The formula should compare the text entries in 3 columns on the right
and check to see whether the date is less than or equal to the date in
the current column. If true (ie less than or equal to) it needs to
return a 1 in that position else 0.