microtime-x - Get current time in microseconds (cross-environment solution)
Returns the number of microseconds elapsed since 1 January 1970 00:00:00 UTC
In browser relies on performance.now or it's engine specific variant if available, in Node.js microtime-nodejs by yuri0 is used (if supported). If none of the mentioned works then Date.now() result multiplied by 1000 is returned
Installation
NPM
In your project path:
$ npm install @limeandcoconut/microtime-x
Browser
You can easily bundle npm packages for browser with modules-webmake
Tests 
$ npm test