import { performance } from "https://deno.land/x/deno@v1.0.0/cli/js/lib.deno.shared_globals.d.ts";
const { now } = performance;
Returns a current time from Deno's start in milliseconds.
Use the flag --allow-hrtime return a precise value.
const t = performance.now();
console.log(`${t} ms since start!`);