How to create y-axis separation lines?

I have a graph where a part of the data is some days in the future and the other part is in the past.

Is it possible to add y-axis separation lines (between past and future or on day change)?

Can you draw what mean?

The green line indicates the border between past and future. It makes it a lot easier to read the graph, cause i dont have to look at the x axis and think about the dates.

A separation line would also be handy with other scenarios. eg: mark the time where a valve switched, backup started, etc