diff --git a/portal/server.selfhosted.js b/portal/server.selfhosted.js
index 9597675..a1c3a6e 100644
--- a/portal/server.selfhosted.js
+++ b/portal/server.selfhosted.js
@@ -294,10 +294,18 @@ app.get('/api/portal/notas', authMiddleware, async (req, res) => {
 app.get('/api/portal/frequencia', authMiddleware, async (req, res) => {
   try {
     const { rows: dbAttendance } = await pool.query(
-      'SELECT id, aluno_id as "studentId", turma_id as "classId", TO_CHAR(data, \'YYYY-MM-DD"T"HH24:MI:SS\') as "date", foto as "photo", verificado as "verified", tipo as "type", justificativa as "justification", justificativa_aceita as "justificationAccepted" FROM frequencias WHERE aluno_id = $1',
+      'SELECT id, aluno_id as "studentId", turma_id as "classId", data as "rawDate", foto as "photo", verificado as "verified", tipo as "type", justificativa as "justification", justificativa_aceita as "justificationAccepted" FROM frequencias WHERE aluno_id = $1',
       [req.user.studentId]
     );
-    res.json({ attendance: dbAttendance });
+    // Converter datas para ISO string COM timezone (formato idêntico ao Manager JSON)
+    // O pg driver retorna TIMESTAMPTZ como Date objects do JS, e toISOString() preserva o UTC correto.
+    // O browser então faz new Date(isoString) e converte para hora local automaticamente.
+    const attendance = dbAttendance.map(row => ({
+      ...row,
+      date: row.rawDate instanceof Date ? row.rawDate.toISOString() : (row.rawDate || ''),
+      rawDate: undefined
+    }));
+    res.json({ attendance });
   } catch (err) {
     console.error('Frequencia error:', err);
     res.status(500).json({ error: 'Erro interno' });