Unix timestamp from date

Gets the Unix timestamp from a Date object.

• Use Date.prototype.getTime() to get the timestamp in milliseconds and divide by 1000 to get the timestamp in seconds.
• Use Math.floor() to appropriately round the resulting timestamp to an integer.
• Omit the argument, date, to use the current date.

const getTimestamp = (date = new Date()) => Math.floor(date.getTime() / 1000);

getTimestamp(); // 1602162242