v3.0.2 I got `ReferenceError: Date is not defined` when calling `reset()`. My tests are Babel-compiled on the fly, and I believe this breaks the link between the `Date` reference and the actual `global.Date` class. I have a fix, and would offer a PR but I'm not familiar with typescript. I did copy your earlier js version (27a1a733709da04d9463fa53c9454ff7c3885e17 - Remove Dead Code) and replaced all `Date` references with `global.Date`. This works fine. (Also, by the way, when you merged your ts branch, you accidentally undid the removal of the dead code in the mentioned commit).