JSFiddle - React, Tailwind, and code Playground

JavaScript

alert(roundMinutes(new Date(2011, 1, 1, 4, 29))); // 4:29
alert(roundMinutes(new Date(2011, 1, 1, 4, 55))); // 4:55


function roundMinutes(date) {
    return date.getMinutes() >= 30 ? date.getHours() + 1 : date.getHours();
}