Unfortunately that's not the reason -- all formatting is the same. But
thanks for responding.

"Joel" wrote:

I suspect the last lines are not formated the same as the first lines. One
set of dates is probably text and the other set is microsoft date. Convert
all the dates to the same format.

"Patlee" wrote:

Trying to sort 3 columns (last name-first name-birthday) by birthday. Excel
sorts correctly but only the first 82 rows. It leaves the last 20 rows
unsorted. How can I get it to sort the entire worksheet?