I have this error when I creating users. I tried to restart the server but it's the same. I also tried to restore a precedent version of my database, it works but 2 days and the error come back. Did someone had the same error?

Here the error:

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 499, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 516, in dispatch
    result = self._call_function(**self.params)
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 282, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/service/model.py", line 113, in wrapper
    return f(dbname, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 279, in checked_call
    return self.endpoint(*a, **kw)
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 732, in __call__
    return self.method(*args, **kw)
  File "/usr/local/lib/python2.7/site-packages/openerp/http.py", line 375, in response_wrap
    response = f(*args, **kw)
  File "/var/packages/Odoo8/target/addons/web/controllers/main.py", line 944, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/var/packages/Odoo8/target/addons/web/controllers/main.py", line 936, in _call_kw
    return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 332, in old_api
    result = method(recs, *args, **kwargs)
  File "/var/packages/Odoo8/target/addons/dev_employee_from_user/models/res_users.py", line 22, in create
    'user_id':user.id})
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 235, in wrapper
    return new_api(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 464, in new_api
    result = method(self._model, cr, uid, *args, **kwargs)
  File "/var/packages/Odoo8/target/addons/hr/hr.py", line 284, in create
    employee_id = super(hr_employee, self).create(cr, uid, data, context=context)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/var/packages/Odoo8/target/addons/mail/mail_thread.py", line 377, in create
    thread_id = super(mail_thread, self).create(cr, uid, values, context=context)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 332, in old_api
    result = method(recs, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/models.py", line 3970, in create
    record = self.browse(self._create(old_vals))
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 235, in wrapper
    return new_api(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 464, in new_api
    result = method(self._model, cr, uid, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/models.py", line 4167, in _create
    self.pool[model_name]._store_set_values(cr, user, ids, fields2, context)
  File "/usr/local/lib/python2.7/site-packages/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/openerp/models.py", line 4255, in _store_set_values
    res_date = time.strptime((r[1])[:19], '%Y-%m-%d %H:%M:%S')
  File "/usr/lib/python2.7/_strptime.py", line 478, in _strptime_time
    return _strptime(data_string, format)[0]
  File "/usr/lib/python2.7/_strptime.py", line 332, in _strptime
    (data_string, format))
ValueError: time data '2020-01-11' does not match format '%Y-%m-%d %H:%M:%S'

Thanks