sfm/event_browser.html

@@ -356,6 +356,16 @@ function _psiToDbl(psi) {
   return 20 * Math.log10(psi / DBL_REF);
 }
 
+// Format an ISO timestamp in the browser's local timezone — UTC values
+// (with 'Z' suffix) convert; naive values are interpreted as local clock.
+// Returns '—' for null/empty/unparseable.
+function _fmtTsLocal(iso) {
+  if (!iso) return '—';
+  const d = new Date(iso);
+  if (isNaN(d)) return iso;
+  return d.toLocaleString();
+}
+
 // Adaptive decimal formatter — scientific notation only for truly extreme
 // values.  Normal-range peaks render as plain decimals with sensible
 // precision (was previously forcing toExponential(3) which produced ugly
@@ -458,7 +468,7 @@ function renderEventList() {
     const row = document.createElement('div');
     row.className = 'event-row' + (ev.false_trigger ? ' false_trigger' : '');
     if (ev.id === currentEventId) row.className += ' active';
-    const ts = (ev.timestamp || '').replace('T', ' ').replace('Z', '');
+    const ts = _fmtTsLocal(ev.timestamp);
     const pvs = ev.peak_vector_sum != null ? `${ev.peak_vector_sum.toFixed(3)} in/s` : '—';
     row.innerHTML = `
       <div class="er-top">
@@ -510,7 +520,7 @@ function renderMeta(data, ev) {
   const metaDiv = document.getElementById('event-meta');
   const fields = [
     ['Serial',      data.serial || ev?.serial || '—'],
-    ['Timestamp',   (data.timestamp || ev?.timestamp || '—').replace('T', ' ').replace('Z', '')],
+    ['Timestamp',   _fmtTsLocal(data.timestamp || ev?.timestamp)],
     ['Record',      data.record_type || ev?.record_type || '—'],
     ['Sample rate', data.sample_rate ? `${data.sample_rate} sps` : '—'],
     ['Geo range',   data.geo_range ? `${data.geo_range} (${data.geo_full_scale_ips} in/s FS)` : '—'],

sfm/sfm_webapp.html

@@ -2864,7 +2864,9 @@ function _renderSidecar(data) {
   };
 
   document.getElementById('sc-f-serial').textContent   = ev.serial          || '—';
-  document.getElementById('sc-f-ts').textContent       = ev.timestamp       || '—';
+  // Route through _fmtTs so the unit-local naive timestamp shows as
+  // "5/27/2026, 6:00:13 AM" instead of "2026-05-27T06:00:13".
+  document.getElementById('sc-f-ts').textContent       = _fmtTs(ev.timestamp);
   document.getElementById('sc-f-rt').textContent       = ev.record_type     || '—';
   document.getElementById('sc-f-sr').textContent       = (ev.sample_rate ?? '—') + (ev.sample_rate ? ' sps' : '');
   document.getElementById('sc-f-key').textContent      = ev.waveform_key    || '—';
@@ -2884,7 +2886,10 @@ function _renderSidecar(data) {
   document.getElementById('sc-f-bwsize').textContent   = bw.filesize != null ? `${bw.filesize} bytes` : '—';
   document.getElementById('sc-f-sha').textContent      = bw.sha256          || '—';
   document.getElementById('sc-f-src').textContent      = src.kind           || '—';
-  document.getElementById('sc-f-cap').textContent      = src.captured_at    || '—';
+  // captured_at has a "Z" suffix (UTC); _fmtTs converts to browser local
+  // — matches the BW-reported recorded-at, no more "21:59:57 vs it's 6 PM"
+  // confusion from operators reading the raw UTC value.
+  document.getElementById('sc-f-cap').textContent      = _fmtTs(src.captured_at);
 
   document.getElementById('sc-edit-ft').checked        = !!rev.false_trigger;
   document.getElementById('sc-edit-reviewer').value    = rev.reviewer || '';