charts: fixed x axis data format does not work well with short periods

## Expected Behavior

x axis text should adapt to the interval or be configurable

## Current Behavior

x axis has fixed day/month text

## Possible Solution

* decide based on interval
* make it configurable

## Steps to Reproduce

render a chart with a 12h intervall

## Context

render a chart with a 12h intervall

## Your Environment

- Version used: `master`

## Screenshots

Start by reproducing the chart with a 12h interval and inspect where the x-axis day/month text is formatted. Determine whether the interval-based behavior or configurability is the appropriate scope, then verify that the displayed labels adapt correctly for short periods.

Written by the indexing model from the issue text.