Date not compatible with locale in Follow-up task on Opportunity

[AltiusRupert]

I am using Logger on a French iPhone.
When I click "Follow Up" on an Opportunity, I cannot save the task if I have input a date : the Save button is disabled, presumably because the (French) date format is not the format expected by the app.
I cannot edit the date manually.

=> dates cannot be used in Logger in non-US locales !