So you want to have a nice digital clock on your system! It’s only logical.
Easiest way to do it is with HACS + digital-clock custom card.

Let’s get to it:

  1. Go to HACS
  2. Go to Frontend tab
  3. Click on the button – Explore & Add repositories
  4. Search for digital-clock
  5. Install and refresh when asked to
  6. Go to your dashboard -> edit
  7. Add a new card
  8. Select custom:digital-clock
  9. Adjust to your liking by the documentation. You can use locale to display it in your language and format.
type: 'custom:digital-clock'
dateFormat:
  weekday: 'long'
  day: '2-digit'
  month: 'short'
timeFormat:
  hour: '2-digit'
  minute: '2-digit'

Read more on Github