setInterval.js

var start = null;

function step(timestamp) {
    // console.log(timestamp);

    if (!start) {
        start = timestamp;
    }

    var progress = timestamp - start;

    if (progress > 1000) {
        console.log("moveRainDropDown");
        start = timestamp;
    }

    window.requestAnimationFrame(step);
}

window.requestAnimationFrame(step);