Comment by pkasting

When I led C++ style/modernization for Chromium, I made this argument frequently: we should prefer the stdlib version of something unless we have reason not to, because incoming engineers will know it, you can find advice on the internet about it, clang-tidy passes will be written for it, and it will receive optimizations and maintenance your team doesn't have to pay for.

There are cases, however, when the migration costs are significant enough that even those benefits aren't really enough. Migrating our date/time stuff to <chrono> seemed like one of those.