'get current date and time format, according to the context lang
:return: a tuple with (format date, format time)'

@api.model
def _get_date_formats(self):

    lang = self._context.get('lang')
    lang_params = {}
    if lang:
        record_lang = self.env['res.lang'].search([('code', '=', lang)], limit=1)
        lang_params = {'date_format': record_lang.date_format, 'time_format': record_lang.time_format}
    format_date = lang_params.get('date_format', '%B-%d-%Y').encode('utf-8')
    format_time = lang_params.get('time_format', '%I-%M    %p').encode('utf-8')
    return (format_date, format_time)
