Grafana: Highlight 12 hour intervals in graphs for easier viewing

readme.md

1. Open Grafana dashboard settings.
2. Go to "Annotations"
3. Create an annotation with a data source "InfluxDB" and add the following query:

import "array"
import "timezone"
import "date"

option location = timezone.location(name: "Asia/Bangkok")

array.from(rows:[
  {
    time_from: date.sub(d: 12h, from: today()),
    time: today(),
    text: "yesterday"
  },
  {
    time_from: date.add(d: 12h, to: today()),
    time: date.add(d: 24h, to: today()),
    text: "today"
  }
])

4. Choose a prefered color (I chose the light blue color)
5. Save the dashboard and reload it.
6. Observe: