以来 / 自…以来【yǐlái / zì…yǐlái】

以来 goes after a point in time or an event and covers the whole stretch from then up to the moment of speaking. The sentence describes what has held, or what has happened, across that stretch.

With 自 or 从

A 自, 从 or 自从 in front marks the start point more clearly. 自…以来 is the most formal and the one you meet in news and reports.

With a length of time

After a span such as 三年 or 几个月, 以来 means "over the past …". 长期以来 – "for a long time now" – and 一直以来 are set phrases.

以来 or 以后

以后 is "after" and can point anywhere, including the future. 以来 always runs up to now, so it never goes with a future time or a single event that is over and done.

• × 明年以来 → 明年以后
• × 毕业以来他去了上海 → 毕业以后他去了上海

The predicate after 以来 usually carries 一直, 都, 了 or 过 to show the stretch running on.