Even using a library isn't that practical. It may be the zeitgeist in JavaScript but that doesn't mean it's actually a good idea. Nobody remembers left-pad? If you're writing Java or Python then checking if your date class can already do it is a good idea.
I've managed to work in tech for 30 years without ever significantly coming into contact with javascript professionally. I hire Ada and C programmers for a stodgy defense contractor where we have to wear ties and it takes 6 months to get a new library approved; unicorns don't really thrive in this environment (or in Fairfax County in general).
