转换为CHAR失去夏令时

Question

我有以下查询：

SELECT
    from_tz(CAST(e.Event_Time_UTC AS TIMESTAMP), 'UTC') AS UTC,
    from_tz(CAST(e.Event_Time_UTC AS TIMESTAMP), 'UTC') AT TIME ZONE 'Brazil/East' AS BRT,
    TO_CHAR(from_tz(CAST(e.Event_Time_UTC AS TIMESTAMP), 'UTC') AT TIME ZONE 'Brazil/East', 'HH24:MI') AS Hora
FROM 
    MY_EVENTS e
ORDER BY 
    UTC

我正在接收UTC时间并转换为本地。

当我直接转换时，一切正常，但是当我使用TO_CHAR时，我失去了夏令时，结果看起来像这样：

有人可以解释一下发生了什么吗？

编辑：这是v$timezone_file的结果：