[译] 会议安排在星期六下午举行。
[误] The conference has been arranged on Saturday afternoon.

[正] The conference has been arranged for Saturday afternoon.
[注] 说会议、约会等安排在何时举行, 日期前用 for 而不用 on (用 on 可能会引起歧义, 因为可能会误解为某日决定或安排)。