Uncaught TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'Object'
    --- property 'c' closes the circle
    at JSON.stringify (<anonymous>)
    at <anonymous>:1:17

const a = { x: 20, date: new Date() };
JSON.parse(JSON.stringify(a))
{x: 20, date: '2023-01-04T15:17:02.957Z'}

structuredClone(a)
// {x: 20, date: Wed Jan 04 2023 15:17:02 GMT+0000 (Greenwich Mean Time), c: {…}}