Here's an answer to my own question. I hope it helps others. I've found a solution that works for me in Quicken and Agent. Some apps take the short date format from ~/.wine/drive_c/windows/win.ini and some take it from ~/.wine/user.reg so it is necessary to amend both. In user.reg look for sShortDate= under [Control Panel \\ International] and change to sShortDate="dd/MM/yyyy" . in win.ini look for sShortDate= under [intl] and change to sShortDate="dd/MM/yyyy" .
