Date column sorts alphabetically instead of chronologically in DataTables

The Solution: Use Orthogonal Data

To maintain chronological sorting while displaying regional dates, you must separate the sort value (the raw UTC timestamp) from the display value (the formatted local string). DataTables sorts based on the value it is given; if that value is a formatted string like "October 12", it will sort alphabetically.

Technical Clarifications

• Plugin Behavior: The datetime-moment plugin provides formatting helpers, but it does not automatically solve sorting if the render function only returns a formatted string. You still need to provide a sortable value.
• Conversion Layer: UTC-to-local conversion should occur inside the render function. This ensures the raw data remains untouched for sorting and filtering, while the viewer's browser handles the regional offset.
• Data Pipeline: Performing conversion earlier in the pipeline (before the table) risks losing the original timestamp, which is required for accurate sorting.

Implementation Steps

1. Ensure your data source provides dates as ISO 8601 strings or Unix timestamps.
2. Use a render function in your column definition to return different values based on the type parameter:

{
  data: 'timestamp',
  render: function (data, type, row) {
    if (type === 'sort' || type === 'type') {
      return data; // Return raw UTC timestamp for chronological sorting
    }
    // Convert to local time for display only
    // Using native Intl.DateTimeFormat as a lightweight alternative to Moment.js
    return new Intl.DateTimeFormat(navigator.language, {
      dateStyle: 'medium',
      timeStyle: 'short'
    }).format(new Date(data));
  }
}

1. Alternatively, if using HTML-sourced data, add the data-order attribute to the <td>:

<td data-order="1728854000">Oct 13, 2026, 6:32 PM</td>

Diagnostic Requirement

If you are using server-side processing (serverSide: true), the sorting happens on the database level, not the client. In this case, please confirm if your API response includes the raw timestamp in a separate field for the server to order by.