Vegalite unable to parse dates in format DD/MM/YYYY

[usman1 (Muhammad Usman)]

My log files have the timestamp as 13/10/2020 13:03 and Vegalite visualizations are being broken every time date is more than 12, which means it is taking month as days and vice versa.

Following is the line of code I am using for conversion:

    transform: [
      {
        calculate: "toDate(datum._source.TIMESTAMP)", 
        as: "time"
      }
    ]

TIMESTAMP attribute in the source is as follows:

    "TIMESTAMP" : "15/06/2020 17:18"

[aaron-nimocks]

I don't think toDate function recognizes your format so you need to parse it.

Specification

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "data": [
    {
      "name": "table",
      "values": [{"TIMESTAMP": "15/06/2020 17:18"}],
      "transform": [
        {
          "type": "formula",
          "expr": "timeParse(datum.TIMESTAMP, '%d/%m/%Y %H:%M')",
          "as": "time"
        }
      ]
    }
  ]
}

Returns

** You may need to do another transform for Time Zone depending on your use case. Also I did this in Vega, just need to change it back to calculate vs formula.

[usman1 (Muhammad Usman)]

Thanks @aaron-nimocks for this, really helpful. Just one more query, how can I quickly debug this (the way you showed what it returns)?

[aaron-nimocks]

Use the Vega Editor and on the bottom right click Data Viewer and select the data source by the name you set in the spec.

If you are using a newer version of Kibana you can also do it on there.

[usman1 (Muhammad Usman)]

Thanks so much @aaron-nimocks. Apart from solving the issue, this thread has been helpful in knowing about the Debug feature which I know will be extremely useful in future.