Since Grafana version 7.20 14 (Grafana addon updated 2020-09-23) it is now possible to localize the date format in a env.
read more here 336 about the options
Default is US i.e. MM/DD HH:mm

Update your grafana configuration to DD/MM

plugins: []
env_vars:
  - name: GF_DATE_FORMATS_INTERVAL_HOUR
    value: 'DD/MM HH:mm'
  - name: GF_DATE_FORMATS_INTERVAL_DAY
    value: DD/MM
ssl: true
certfile: fullchain.pem
keyfile: privkey.pem

Source: Grafana change date format – tip of the day – Configuration – Home Assistant Community