Generalize study release-date gating across all studies

server.js

@@ -114,10 +114,26 @@ function sanitizeUrl(value) {
   return ''
 }
 
+function getSectionReleaseTime(section) {
+  if (!section || typeof section !== 'object') return Number.NaN
+  const candidateValues = [
+    section.releasedAt,
+    section.releaseDate,
+    section.availableAt,
+    section.publishAt,
+  ]
+
+  for (const candidate of candidateValues) {
+    if (typeof candidate !== 'string' || !candidate.trim()) continue
+    const releaseTime = Date.parse(candidate)
+    if (Number.isFinite(releaseTime)) return releaseTime
+  }
+
+  return Number.NaN
+}
+
 function isSectionReleased(section) {
-  if (!section || typeof section !== 'object') return false
-  if (typeof section.releasedAt !== 'string' || !section.releasedAt.trim()) return false
-  const releaseTime = Date.parse(section.releasedAt)
+  const releaseTime = getSectionReleaseTime(section)
   if (!Number.isFinite(releaseTime)) return false
   return releaseTime <= Date.now()
 }