I used jQuery so the code is cleaner - however I will make an non-jQuery version because you don't need jQuery! But I used it to get this faster done - and the code stays more compact.

Demo:

https://codebrauer.github.io/27daysofcode/020_2017-01-23_JS_nthChildTester

Log: The 3 days pause was caused by illness, project finish date will be also 3 days later.