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+* Sun
+
+~sun~ wraps [[https://github.com/nathan-osman/go-sunrise][go-sunrise]] to calculate sunrise, sunset, and day length for a location.
+
+** Usage
+
+#+begin_src shell
+sun -c LAT,LON [-d YYYY-MM-DD] [-z TIMEZONE] [-f FORMAT]
+#+end_src
+
+Flags:
+
+- =-c= — coordinates as =latitude,longitude= (required)
+- =-d= — date in =YYYY-MM-DD= format (default: today)
+- =-z= — timezone (default: UTC)
+- =-f= — output time format, [[https://pkg.go.dev/time#Time.Format][Go reference layout]] (e.g. =15:04= for HH:MM; default: RFC 3339)
+
+The tool outputs three values: sunrise (time), sunset (time), and day length (duration).
+
+** Examples
+
+#+begin_src shell
+$ sun -c 51.4769,0.0005
+2026-10-23T06:37:08Z 2026-10-23T16:51:16Z 10h14m8s
+
+$ sun -c -77.8419,166.6863 \
+  -d 2026-03-20 \
+  -z Antarctica/McMurdo \
+  -f "15:04"
+07:38 20:23 12h45m28s
+#+end_src
+
+** Installation
+
+#+begin_src shell
+go install code.chimeric.al/dwrz/sun/cmd/sun@latest
+#+end_src