To only drawn the text once you can use the select transform: Plot.text(data, Plot.selectFirst({ x: 0.1, y: 12, textAnchor: "start", text: (d) => d.date.toLocaleString("en", {month: "long"}) })) Also I recommend using English rather than the browser’s locale since the rest of the page is in English already and it looks odd to mix locales.

ooh - thank you! And, thank you for the suggestion / update regarding Locale string! I copy/pasted from a stackoverflow answer and only briefly wondered what the 'undefined' was doing :). Good learning for the future too.