You can use libffi and so windows/posix time facilities at compile-time with the hidden flags mentionned in this PR:
[https://github.com/nim-lang/Nim/pull/10150#issuecomment-462660376](https://github.com/nim-lang/Nim/pull/10150#issuecomment-462660376) -d:nimHasLibFFI for the compiler| ---|--- \--experimental:compiletimeFFI for the compiled code|
