Locale relative date parsing error

[Baboon-Delaware]

Hi,

I have a problem running markwhen on a FR locale system :
Everytime I resize a task using the timeline view (or gantt view), relative dates are translated to french (I think due to my system configuration).

Here is an example :
I set a task to a 1 week duration :

Then I use the right drag & drop handler to set the task to a 2 weeks duration :

The task disappear and the text is tranlated to french.

Please let me know if you have any workaround to resize task in the UI, haven't found any yet !