API access differs from that of Date

Is it intentional for the package's API access to differ from that of Date? I initially expected the package to work as a drop-in replacement of `Date.now()` by exporting a function by the name of `now()` rather than an object with a property by the name of `now`.

Is this something you'd allow a PR to change? I have a branch with performance increases adding up to a little over 100%. I'd like to create a PR for it but it's based on an API refactor that would close this issue.