Converts a time difference between a given time and the current time to a human friendly string (a.k.a timeago, moments)

humanTimeDiff.ts

const frames = [
    { name: "year", value: (d: number) => Math.floor(d / 29030400000) },
    { name: "month", value: (d: number) => Math.floor(d / 2419200000) },
    { name: "week", value: (d: number) => Math.floor(d / 604800000) },
    { name: "day", value: (d: number) => Math.floor(d / 86400000) },
    { name: "hour", value: (d: number) => Math.floor(d / 3600000) },
    { name: "minute", value: (d: number) => Math.floor(d / 60000) },
    { name: "second", value: (d: number) => Math.floor(d / 1000) },
];
function humanTimeDiff(date: Date, frame: number = 0) {
    const now = new Date();
    const diff = date.getTime() - now.getTime();
    const t = diff < 0 ? "ago" : "left";
    if (frame >= frames.length) {
        return "now";
    }
    const f = frames[frame];
    const v = f.value(Math.abs(diff));
    if (v === 0) {
        return humanTimeDiff(date, frame + 1);
    }
    return `${Math.abs(v)} ${f.name}${Math.abs(v) !== 1 ? "s" : ""} ${t}`;
}
humanTimeDiff(new Date("Tue Jan 29 2019 16:50:10 GMT+0100")); //?