diff --git a/field-logic/src/components/TranscriptViewer.test.ts b/field-logic/src/components/TranscriptViewer.test.ts
new file mode 100644
index 0000000..202238c
--- /dev/null
+++ b/field-logic/src/components/TranscriptViewer.test.ts
@@ -0,0 +1,22 @@
+import { describe, it, expect } from "vitest";
+import { formatTimestamp } from "./TranscriptViewer";
+
+describe("TranscriptViewer", () => {
+  describe("formatTimestamp", () => {
+    it("formats 0 seconds correctly", () => {
+      expect(formatTimestamp(0)).toBe("00:00");
+    });
+
+    it("formats seconds less than a minute correctly", () => {
+      expect(formatTimestamp(45)).toBe("00:45");
+    });
+
+    it("formats minutes and seconds correctly", () => {
+      expect(formatTimestamp(65)).toBe("01:05");
+    });
+
+    it("formats longer durations correctly (ignoring hours)", () => {
+      expect(formatTimestamp(3665)).toBe("01:05");
+    });
+  });
+});
diff --git a/field-logic/src/components/TranscriptViewer.tsx b/field-logic/src/components/TranscriptViewer.tsx
index 9929047..54d95b7 100644
--- a/field-logic/src/components/TranscriptViewer.tsx
+++ b/field-logic/src/components/TranscriptViewer.tsx
@@ -1,74 +1,90 @@
-import React from 'react';
+import React from "react";
 
 interface TranscriptSegment {
-    start: number;
-    end: number;
-    text: string;
-    confidence: number;
-    flagged?: boolean;
+  start: number;
+  end: number;
+  text: string;
+  confidence: number;
+  flagged?: boolean;
 }
 
 interface TranscriptData {
-    meta: {
-        file: string;
-        duration: number;
-        engine: string;
-    };
-    segments: TranscriptSegment[];
+  meta: {
+    file: string;
+    duration: number;
+    engine: string;
+  };
+  segments: TranscriptSegment[];
 }
 
 interface Props {
-    data: TranscriptData;
+  data: TranscriptData;
 }
 
+export const formatTimestamp = (start: number): string => {
+  return new Date(start * 1000).toISOString().substring(14, 19);
+};
+
 export const TranscriptViewer: React.FC<Props> = ({ data }) => {
-    const handleDeepLink = (e: React.MouseEvent, start: number) => {
-        e.preventDefault();
-        const file = data.meta.file;
-        // Construct custom protocol link
-        const url = `fieldlogic://open?file=${file}&t=${start}`;
-        window.location.href = url;
-    };
+  const handleDeepLink = (e: React.MouseEvent, start: number) => {
+    e.preventDefault();
+    const file = data.meta.file;
+    // Construct custom protocol link
+    const url = `fieldlogic://open?file=${file}&t=${start}`;
+    window.location.href = url;
+  };
 
-    return (
-        <div className="transcript-viewer" style={{ maxWidth: '800px', margin: '0 auto', fontFamily: 'monospace' }}>
-            <h2>Transcription Review: {data.meta.file}</h2>
+  return (
+    <div
+      className="transcript-viewer"
+      style={{ maxWidth: "800px", margin: "0 auto", fontFamily: "monospace" }}
+    >
+      <h2>Transcription Review: {data.meta.file}</h2>
 
-            <div className="segments">
-                {data.segments.map((seg, idx) => (
-                    <div
-                        key={idx}
-                        style={{
-                            padding: '8px',
-                            borderBottom: '1px solid #eee',
-                            backgroundColor: seg.confidence < 0.6 ? '#fef3c7' : 'transparent'
-                        }}
-                    >
-                        <span style={{ color: '#64748b', marginRight: '10px', userSelect: 'none' }}>
-                            [{new Date(seg.start * 1000).toISOString().substr(14, 5)}]
-                        </span>
+      <div className="segments">
+        {data.segments.map((seg, idx) => (
+          <div
+            key={idx}
+            style={{
+              padding: "8px",
+              borderBottom: "1px solid #eee",
+              backgroundColor: seg.confidence < 0.6 ? "#fef3c7" : "transparent",
+            }}
+          >
+            <span
+              style={{
+                color: "#64748b",
+                marginRight: "10px",
+                userSelect: "none",
+              }}
+            >
+              [{formatTimestamp(seg.start)}]
+            </span>
 
-                        <span style={{ marginRight: '10px' }}>{seg.text}</span>
+            <span style={{ marginRight: "10px" }}>{seg.text}</span>
 
-                        <div style={{ float: 'right' }}>
-                            {/* Primary: In-browser audio (mock) */}
-                            <button onClick={() => console.log('Seek audio to', seg.start)} style={{ marginRight: '5px' }}>
-                                ▶
-                            </button>
+            <div style={{ float: "right" }}>
+              {/* Primary: In-browser audio (mock) */}
+              <button
+                onClick={() => console.log("Seek audio to", seg.start)}
+                style={{ marginRight: "5px" }}
+              >
+                ▶
+              </button>
 
-                            {/* Secondary: VLC Deep Link */}
-                            <a
-                                href="#"
-                                onClick={(e) => handleDeepLink(e, seg.start)}
-                                title="Open in VLC"
-                                style={{ textDecoration: 'none' }}
-                            >
-                                🚀
-                            </a>
-                        </div>
-                    </div>
-                ))}
+              {/* Secondary: VLC Deep Link */}
+              <a
+                href="#"
+                onClick={(e) => handleDeepLink(e, seg.start)}
+                title="Open in VLC"
+                style={{ textDecoration: "none" }}
+              >
+                🚀
+              </a>
             </div>
-        </div>
-    );
+          </div>
+        ))}
+      </div>
+    </div>
+  );
 };