// RxJS v6+
import { interval } from 'rxjs';
import { skipWhile } from 'rxjs/operators';
​
//emit every 1s
const source = interval(1000);
//skip emitted values from source while value is less than 5
const example = source.pipe(skipWhile(val => val < 5));
//output: 5...6...7...8........
const subscribe = example.subscribe(val => console.log(val));