Posted 15 September 2008 - 02:24 AM
Tidiest way to do what you want, I suspect, crlare, is in Outlook where you can schedule a meeting and/or share Free/Busy information as standard functions - look up the voluminous Outlook Help files. But that suits the corporate group and may not be viable with a "mob" of volunteers.
EXCEL has a dozen ways of copying those processes, but these are all applications, not simple straightforward functions or formats. They all start with a database of availabilities. A spreadsheet might have hours down Column A, and "n" following columns, each somehow logging the availability of one of your n volunteers. I'd use the volunteer's initials in the cells of his/her column when available. Then Column (n+2) could include group availability.
If you only cared about headcount, that column can contain a COUNTA function. Pick the number closest to n for largest attendance.
But if you're fussed about who can attend, use the & function to collect a series of text strings of initials,like
=C2 & C3 & C4
or more tidily, =IF(C2>"",C2 & ", ") & IF(C3>"",C3 & ", ") & IF(C4>"",C4)
and even include some COUNTIF term to narrow the search in order to always include certain key people.
That's a bit of work to set up.... You might want to Share the EXCEL workbook with volunteers and ask them to keep their own column updated, and so use the same work base over and over.
Enjoy the challenge of herding volunteers.