Reading the charts

Every chart in Atlas is rendered by one shared component with one shared set of options, so the conventions below hold across the whole site. Learn them once.

Time is UTC

Time axes, tick labels and tooltips are all UTC, and tooltips that include a clock time say so explicitly (2026-08-10 14:00 UTC).

This is deliberate rather than incidental. The underlying series are bucketed by UTC day or hour, so rendering them in the viewer's local zone would shift every point by your offset and silently mislabel the buckets — a chart that looks fine and is wrong. If a value seems shifted by a few hours, the conversion is almost certainly happening in your own head or your own code, not in the chart.

The exception is a handful of sub-minute series where "when did this happen for me" is the actual question. Those render in local time, and their tooltips omit the UTC suffix — which is how you tell the two apart.

Tooltips

Hovering gives you the timestamp as a header and one row per series, each with its color marker, the series name and the value. Series with no value at that point are omitted from the tooltip rather than shown as zero — see Gaps below.

Numbers are rounded and thousands-separated for display. If you need exact values, read them from the API rather than the chart.

Legends

Charts with more than one series carry a legend; click an entry to hide or show that series. Hidden series stay hidden while you stay on the page.

On narrow viewports the legend is dropped and axis labels are thinned out to keep the plot readable. Nothing is removed from the data — rotate to landscape or widen the window to get the legend back.

Zooming

Where a chart supports it, you can drag or scroll on the x-axis to zoom into a period, and there is a zoom control below the plot to reset. Today the data-delay chart is the one that carries this — it is the view where "what happened in that one bad hour" is a real question.

Exporting

Charts intended for slide decks carry a save-as-image control in the top-right toolbox; the new probes chart is the current example. It saves what is on screen, including any zoom and hidden series.

Empty states

An empty series renders as a message — "No data in the selected range." — rather than a set of bare axes. If you see that, the query ran and returned nothing; it is not a failed load.

Gaps versus zeroes

A break in a line is missing data. A line that touches zero is a measured zero. The two look different on purpose, and conflating them is the most common way to misread a trend here.

Missing data usually means one of three things: the period predates the archive, the ingestion pipeline was behind, or an upstream was unavailable. Before reading anything into a gap, check data delay — several series are built from archived data that lags real time, and a chart that stops short of today is normally telling you about the pipeline rather than about the internet.

Dark mode

Charts are drawn on canvas and re-render with a resolved palette when you flip the theme, so they follow the site rather than staying light on a dark page. If a chart ever looks wrong immediately after a theme switch, a page reload will settle it.