jQuery has a direct function to access data-* attributes: [.data()](http://api.jquery.com/data/).

The `[data-timestamp]` in `i[data-timestamp]` isn't necessary as there is only one `<i>` per row, just `i` should be enough.
(It should really have a class instead and shouldn't be an `<i>` at all, but that's how the original is and it's not worth changing right now. The same is true for the `.odd,.even`. It should really have an additional class, but that's a bit off-topic and shouldn't be part of this PR.)