No this can not be done.

IBExpert would probably format it according to your local region
settings. It would be a nightmare if you had to configure Firebird to a
specific format. As much as I hate the mm/dd/yyyy format, I am
comforted to know that if I pass in 6/1/2005 I know what date firebird
will interpret that as.

You have not said which language you are using, but many of them allow
you to set parameters, which is the best way to go.

eg:

qry.sql.text := 'insert into tbl values (:mydate)';
qry.parambyname('mydate').asdate := dtp.date;
qry.execsql;

Alternatively, if you want to pass it in as a string literal (which the
FB engine is then going to have to reverse back into a date internally
anyhow), then most languages have some sort of FormatDateTime routine.

eg

FormatDateTime('m/d/yyyy', dtp.Date);

But use parameters, it makes things so much easier on you and takes
care of quoting things where quotes are needed.

Adam