timestamp -> string (example:12172617261 -> 11 min ago)

TimeDifference.js

export function TimeDifference(current, previous) {

    let msPerMinute = 60 * 1000;
    let msPerHour = msPerMinute * 60;
    let msPerDay = msPerHour * 24;
    let msPerMonth = msPerDay * 30;
    let msPerYear = msPerDay * 365;

    let elapsed = current - previous;

    if (elapsed < msPerMinute && Math.round(elapsed / 1000) === 0) {
        return 'now';
    }

    if (elapsed < msPerMinute) {
        return 'now';
    }

    else if (elapsed < msPerHour) {
        return Math.round(elapsed / msPerMinute) + ' min ago';
    }

    else if (elapsed < msPerDay) {
        return Math.round(elapsed / msPerHour) + ' hours ago';
    }

    else if (elapsed < msPerMonth) {
        return Math.round(elapsed / msPerDay) + ' days ago';
    }

    else if (elapsed < msPerYear) {
        return Math.round(elapsed / msPerMonth) + ' months ago';
    }

    else {
        return Math.round(elapsed / msPerYear) + ' years ago';
    }
}