Show input_datetime in UI


I use the frontend to set trigger times for automations. The triggers are pre-defined (list on the right) and can be modified manually if you like via the UI on the left side.

If I do not want to trigger at 00:00 (default) how can i replace the time with a dummy, eg “–:–” ? I can disable the automation and then the trigger will not happen, but the UI always shows the wrong time “00:00” from the default configuration.
Any ideas how to overwrite the time “00:00” with a dummy " --:–" ?