Interactive graph

vega.json

{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.json",
  "data": {
    "url": "https://gist.githubusercontent.com/digi0ps/eacf81d38aafb1a387da605319c50042/raw/47c9fe4100dc2d71ac16b2202754693791bd0036/blah.csv",
    "format": {
      "type": "csv",
      "parse": {
        "date": "date"
      }
    }
  },
  "width": 800,
  "height": 400,
  "layer": [
    {
      "encoding": {
        "x": {
          "field": "Date",
          "type": "temporal"
        },
        "y": {
          "field": "Delay",
          "type": "quantitative"
        }
      },
      "layer": [
        {
          "mark": "line"
        },
        {
          "selection": {
            "tooltip": {
              "type": "single",
              "nearest": true,
              "on": "mouseover",
              "encodings": [
                "x"
              ],
              "empty": "none",
              "resolve": "global"
            }
          },
          "mark": "point",
          "encoding": {
            "opacity": {
              "condition": {
                "selection": "tooltip",
                "value": 1
              },
              "value": 0
            }
          }
        }
      ]
    },
    {
      "transform": [
        {
          "filter": {
            "selection": "tooltip"
          }
        }
      ],
      "layer": [
        {
          "mark": {
            "type": "text",
            "align": "left",
            "dx": 10,
            "dy": 10,
            "size": 15
          },
          "encoding": {
            "text": {
              "type": "quantitative",
              "field": "Delay"
            },
            "x": {
              "type": "temporal",
              "field": "Date"
            },
            "y": {
              "type": "quantitative",
              "field": "Delay"
            },
            "color": {
              "condition": {
                "test": "datum.Delay < 0",
                "value": "green"
              },
              "value": "red"
            }
          }
        }
      ]
    }
  ]
}