Gil Epshtain

@elgs - I like your answer, you can even make it one-liner with: `this.items = [...this.items, ('NEW - ' + this.items.length)];` However, you need to remember that "virtual-scroll" directive purpose...

@elgs - I think the best way to test this is with a real world example - once I've implement this - I'll return with conclusions

@marcgrabow, who is "this.picker"? how did you get a reference to this object?

I've solve this problem by defining a CustomDateAdapter. You can find to full answer here: https://stackoverflow.com/questions/51634726/how-to-change-angular-material-datepicker-format-in-run-time/51696436#51696436