Definition
To inform someone in advance about something that is about to happen, usually to allow them to prepare.
事先通知
I just wanted to give you a heads up that next week's meeting has been moved to Wednesday.
我只是想提醒你，下周的会议已经改到星期三了。
He gave me a heads up that the boss is not in a good mood today.
他提醒我今天老板心情不好。
We should give our clients a heads up about the system maintenance.
我们应该提前通知客户关于系统维护的事。