bin: now / timestamp

bin/now

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+style="${1:-iso}"
+flags=()
+if [[ "${style}" =~ -utc ]]; then
+    style="${style%-utc}"
+    flags+=('--utc')
+fi
+
+format=''
+case "${style}" in
+    iso)   format='--iso-8601=seconds' ;;
+    date)  format='+%Y-%m-%d'          ;;
+    human) format='+%Y-%m-%d %H:%M %z' ;;
+    unix)  format='+%s'                ;;
+    js)    format='+%s%3N'             ;;
+    fs)    format='+%Y%m%d_%H%M%S'     ;;
+    zone)  format='+%z'                ;;
+
+    *)
+        >&2 echo "Unknown format: ${style}"
+        exit 1
+        ;;
+esac
+
+exec date "${flags[@]}" "${format}"