Grafana - show metric grouped by day is shifted by 1 day

I am using Grafana v8.4.4 to visualize Docker container metrics. I would like to show amount of received traffic (upload), grouped by day. For this purpose, I am using container_network_receive_bytes_total metric provided by cAdvisor.

I am using the following Prometheus query:

sum(increase(container_network_receive_bytes_total[1d]))

Once visualized in Grafana, it looks like this (user selected Last 7 days at the top right of Grafana UI). I set Min step to 1d (red rectangle in the photo):

enter image description here

enter image description here

I am writing this post on 6-Apr-2022. I noticed that the days in the graph are off by 1:

  1. Today’s data isn’t displayed on the graph at all
  2. The bar on the far right actually shows data from yesterday (5-Apr-2022), but its label still says 6-Apr-2022

I found a “hack” to show today’s data as well. I had to set Time shift in query options to -1d (0d+1d in Grafana syntax):

enter image description here

enter image description here

Questions:

  1. Why are dates off by 1 day? How can I fix this?
  2. Why are there there 8 bars despite the fact that I selected Last 7 days?

can you share your dashboard json? What are the time settings in the timepicker? Are you using browser time?

This is dashboard JSON:

{
  "annotations": {
    "list": [
      {
        "builtIn": 1,
        "datasource": "-- Grafana --",
        "enable": true,
        "hide": true,
        "iconColor": "rgba(0, 211, 255, 1)",
        "name": "Annotations & Alerts",
        "target": {
          "limit": 100,
          "matchAny": false,
          "tags": [],
          "type": "dashboard"
        },
        "type": "dashboard"
      }
    ]
  },
  "editable": true,
  "fiscalYearStartMonth": 0,
  "graphTooltip": 0,
  "id": 20,
  "links": [],
  "liveNow": false,
  "panels": [
    {
      "fieldConfig": {
        "defaults": {
          "color": {
            "mode": "palette-classic"
          },
          "custom": {
            "axisLabel": "",
            "axisPlacement": "auto",
            "axisSoftMin": 0,
            "fillOpacity": 80,
            "gradientMode": "none",
            "hideFrom": {
              "legend": false,
              "tooltip": false,
              "viz": false
            },
            "lineWidth": 1,
            "scaleDistribution": {
              "type": "linear"
            }
          },
          "mappings": [],
          "thresholds": {
            "mode": "absolute",
            "steps": [
              {
                "color": "green",
                "value": null
              },
              {
                "color": "red",
                "value": 80
              }
            ]
          },
          "unit": "bytes"
        },
        "overrides": []
      },
      "gridPos": {
        "h": 9,
        "w": 12,
        "x": 0,
        "y": 0
      },
      "hideTimeOverride": true,
      "id": 2,
      "options": {
        "barRadius": 0,
        "barWidth": 0.97,
        "groupWidth": 0.7,
        "legend": {
          "calcs": [],
          "displayMode": "list",
          "placement": "bottom"
        },
        "orientation": "auto",
        "showValue": "auto",
        "stacking": "none",
        "tooltip": {
          "mode": "single",
          "sort": "none"
        },
        "xTickLabelRotation": 0,
        "xTickLabelSpacing": 0
      },
      "targets": [
        {
          "datasource": {
            "type": "prometheus",
            "uid": "PBFA97CFB590B2093"
          },
          "exemplar": true,
          "expr": "sum(increase(container_network_receive_bytes_total{container_label_com_docker_stack_namespace=\"BlogBackend\"}[1d]))",
          "interval": "1d",
          "legendFormat": "",
          "refId": "A"
        }
      ],
      "timeShift": "0d+1d",
      "title": "Ingress traffic",
      "type": "barchart"
    }
  ],
  "refresh": "",
  "schemaVersion": 35,
  "style": "dark",
  "tags": [],
  "templating": {
    "list": []
  },
  "time": {
    "from": "now-7d",
    "to": "now"
  },
  "timepicker": {},
  "timezone": "",
  "title": "Test dashboard (delete later)",
  "uid": "HJuRoaUnz",
  "version": 2,
  "weekStart": ""
}

I selected “Last 7 days” in time picker at the top right corner of Grafana GUI.

I am using browser time (UTC+02:00).