diff --git a/tui/tui.go b/tui/tui.go
index bfa056f..6f54360 100644
--- a/tui/tui.go
+++ b/tui/tui.go
@@ -540,6 +540,23 @@ func previewLines(lines []string, n int) []string {
 	return out
 }
 
+// formatElapsed renders a running task's elapsed time, at a precision that
+// suits its scale: mm:ss under an hour, h:mm:ss under a day, and kubectl's
+// compact d+h notation beyond that, where seconds are just noise.
+//
+// The longest output is 8 characters ("23:59:59", or "1000d23h"), which is
+// what sizes the card's elapsed column.
+func formatElapsed(d time.Duration) string {
+	d = d.Round(time.Second)
+	if days := int(d.Hours()) / 24; days > 0 {
+		return fmt.Sprintf("%dd%dh", days, int(d.Hours())%24)
+	}
+	if h := int(d.Hours()); h > 0 {
+		return fmt.Sprintf("%d:%02d:%02d", h, int(d.Minutes())%60, int(d.Seconds())%60)
+	}
+	return fmt.Sprintf("%02d:%02d", int(d.Minutes()), int(d.Seconds())%60)
+}
+
 // renderCard renders a task as a boxed card.
 // Non-selected: 3 lines (top border + content + bottom border).
 // Selected: 3 + len(preview) lines.
@@ -549,8 +566,7 @@ func renderCard(r *agentfleet.Runner, selected bool, w int, preview []string, fr
 	badge := statusBadge(r.Status(), frameCount)
 	elapsed := ""
 	if r.Status() == agentfleet.StatusRunning {
-		d := time.Since(r.StartedAt()).Round(time.Second)
-		elapsed = fmt.Sprintf("%02d:%02d", int(d.Minutes()), int(d.Seconds())%60)
+		elapsed = formatElapsed(time.Since(r.StartedAt()))
 	}
 
 	task := r.Task()
@@ -562,7 +578,8 @@ func renderCard(r *agentfleet.Runner, selected bool, w int, preview []string, fr
 	}
 
 	idStr := idStyle.Render(shortID(task.ID()))
-	elapsedStr := styleMeta.Width(5).Render(elapsed)
+	// Width fits "25:01:02"; shorter values are padded to keep the column aligned.
+	elapsedStr := styleMeta.Width(8).Render(elapsed)
 	rightStr := idStr + "  " + elapsedStr
 	leftPrefix := cursor + badge + "  "
 
diff --git a/tui/tui_test.go b/tui/tui_test.go
new file mode 100644
index 0000000..fb8dc91
--- /dev/null
+++ b/tui/tui_test.go
@@ -0,0 +1,53 @@
+package tui
+
+import (
+	"testing"
+	"time"
+)
+
+func TestFormatElapsed(t *testing.T) {
+	tests := []struct {
+		name string
+		in   time.Duration
+		want string
+	}{
+		{"zero", 0, "00:00"},
+		{"seconds", 5 * time.Second, "00:05"},
+		{"sub-second rounds", 5*time.Second + 400*time.Millisecond, "00:05"},
+		{"minutes", 90 * time.Second, "01:30"},
+		{"just under an hour", 59*time.Minute + 59*time.Second, "59:59"},
+		{"exactly one hour", time.Hour, "1:00:00"},
+		{"hours minutes seconds", time.Hour + 15*time.Minute + 30*time.Second, "1:15:30"},
+		{"just under a day", 23*time.Hour + 59*time.Minute + 59*time.Second, "23:59:59"},
+		{"exactly one day", 24 * time.Hour, "1d0h"},
+		{"day drops seconds", 25*time.Hour + time.Minute + 2*time.Second, "1d1h"},
+		{"multi-day", 2*24*time.Hour + 3*time.Hour + 15*time.Minute, "2d3h"},
+		{"two weeks", 14 * 24 * time.Hour, "14d0h"},
+		{"a year", 365*24*time.Hour + 23*time.Hour, "365d23h"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := formatElapsed(tc.in); got != tc.want {
+				t.Errorf("formatElapsed(%v) = %q, want %q", tc.in, got, tc.want)
+			}
+		})
+	}
+}
+
+// TestFormatElapsedFitsColumn pins the invariant that sizes the card's elapsed
+// column: lipgloss wraps rather than truncates when content exceeds Width, so
+// an over-long value would corrupt the card layout.
+func TestFormatElapsedFitsColumn(t *testing.T) {
+	const columnWidth = 8
+	for _, d := range []time.Duration{
+		0,
+		59*time.Minute + 59*time.Second,
+		23*time.Hour + 59*time.Minute + 59*time.Second,
+		365 * 24 * time.Hour,
+		999*24*time.Hour + 23*time.Hour,
+	} {
+		if got := formatElapsed(d); len(got) > columnWidth {
+			t.Errorf("formatElapsed(%v) = %q is %d chars, exceeds the %d-wide column", d, got, len(got), columnWidth)
+		}
+	}
+}