Convert seconds to hh:mm:ss format

JavaScript version

// `s` is number of seconds
const formatSeconds = (s) => new Date(s * 1000).toISOString().substr(11, 8);

// Or
const formatSeconds = (s) => new Date(s * 1000).toUTCString().match(/(\d\d:\d\d:\d\d)/)[0];

// Or
const formatSeconds = (s) => [parseInt(s / 60 / 60), parseInt((s / 60) % 60), parseInt(s % 60)].join(':').replace(/\b(\d)\b/g, '0$1');

TypeScript version

const formatSeconds = (s: number): string => new Date(s * 1000).toISOString().substr(11, 8);

// Or
const formatSeconds = (s: number): string => (new Date(s * 1000).toUTCString().match(/(\d\d:\d\d:\d\d)/) as string[])[0];

// Or
const formatSeconds = (s: number): string => (
    [parseInt(`${s / 3600}`), parseInt(`${(s / 60) % 60}`), parseInt(`${s % 60}`)].join(':').replace(/\b(\d)\b/g, '0$1')
);

Examples

formatSeconds(200); // 00:03:20
formatSeconds(500); // 00:08:20