Date Format not reflecting setting

Date Format not reflecting setting

Hello ! We are devellopers and working on Creator. Let me explaine the problem..

We build a function in Creator that receive from CRM with a webhook the moment a field as been modified.

when we work into Creator the Date Format is : dd-mm-yyyy hh:mm:ss
The date we receive from CRM is : yyyy-mm-dd h:mm:ss a

but the bigger problem is that the time zone in CRM is set to -5 east for Montreal (where we are)
the same thing as creator !!! but the time we receive from CRM is 4hour later than Creator !!!!

when we go see inside the user preference all the time zone are ok except for the city in CRM
it says France ? We change it to Canada but after 5-10minutes it change itself back to France.

Please note that the time we change the city and do some test where it stay Canada the Date Format receive still the same ? 

p.s. the time inside Crm seems to be ok but with this Format :yyyy-mm-dd h:mm:ss a
Hope to find an Answer 
thank you