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+timechart
+=========
+
+A collection of tools to visualize time series data. Each tool takes pairs
+of dates and values in stdin and produces an SVG on stdout.
+
+Example input:
+
+    2026-01-05 4.7
+    2026-01-07 6.5
+    2026-01-09 7.5
+    2026-01-12 10.0
+    2026-01-14 6.8
+    2026-01-16 6.0
+    2026-01-20 7.7
+    2026-01-22 6.4
+
+tc-calmap
+---------
+
+The calmap tool produces a calendar-like heatmap, where each square
+represents a date and the color represents the value.
+
+There are two different rendering modes: calendar and iso. The calendar
+mode produces a graphic that looks like a normal month-by-month calendar.
+The iso mode produces a denser grid where each row is the day of the week
+and each column is an ISO week.
+
+
+    Usage: tc-calmap [OPTIONS]
+
+    Options:
+          --size <SIZE>
+              The size of each square in the heat map (in px)
+
+              [default: 10]
+
+          --padding <PADDING>
+              The padding between the squares (in px)
+
+              [default: 2]
+
+          --colors <COLORS>
+              The color scale
+
+              [default: #e7ebef #deebf7 #c6dbef #9ecae1 #6baed6 #2171b5]
+
+          --unit <UNIT>
+              The unit description to use in the captions
+
+          --log-scale
+              Use a log scale instead of a linear scale
+
+          --mode <MODE>
+              [default: calendar]
+              [possible values: calendar, iso]
+
+      -h, --help
+              Print help (see a summary with '-h')
+
+
+Contributing
+------------
+
+Send questions, bug reports, and patches to jesse@jesterpm.net.