Worflow using wrong date format when a date is filled into a date-field


when i am using the workflow module to handle invoice due-dates etc. i have the problem that everytime the workflow fills in the date automatically ithe date-format in an sent email is: 12/11/2015. (M-D-Y) When i use the Datepicker manual and set the same Date (11-12-2015) (D-M-Y) the email shows the correct date displayed in the format (11-12-2015)

Does anyone know how i can control the dateformat the workflow module is generating?

Will be great to get an answer.

Thank you.

Will be highly interesting for me.