Answers for "how to check current time diff with other time difference in javascript"

js date difference in seconds

var t1 = new Date();
var t2 = new Date();
var dif = t1.getTime() - t2.getTime();

time difference in javascript

//start timer
console.time();
//your code
//example:
let a = 1000 / 90;
let b = a%(100/90*198) ^ 89 >> 1 << 2;
//stop timer
var timeTakenForCodeToRun = console.timeEnd();