From multiple reporting people able to indentify next due report
 

Have multiple people reporting to me on a monthly basis & I include on their
individual spreadsheet the data in a monthly column, what I need to be able
to do is automatically, by formula hopefully, on the summary spreadsheet
include a column that tells me either of the date of the last or next report
due by reference to the data included in theeir spreadsheet? Using 2007 excel