How can I remove milliseconds from a timestamp in JavaScript?

To remove milliseconds from a timestamp in JavaScript, you can use several methods. Here's a breakdown of the most common approaches:

1. Using `Math.floor()`:

- The simplest way is to use `Math.floor()` to round down the timestamp to the nearest whole number, effectively removing the decimal part representing milliseconds.

- This method is suitable when you want to discard the milliseconds completely.

- Example:

const timestampWithMs = 1678886400123;
const timestampWithoutMs = Math.floor(timestampWithMs / 1000) 1000;
console.log(timestampWithoutMs); // Output: 1678886400000

2. Using `parseInt()`:

- `parseInt()` can also be used to truncate the milliseconds. By dividing the timestamp by 1000 and then multiplying by 1000, you effectively remove the milliseconds.

- This method is similar to using `Math.floor()` but might be slightly less performant.

- Example:

const timestampWithMs = 1678886400123;
const timestampWithoutMs = parseInt(timestampWithMs / 1000) 1000;
console.log(timestampWithoutMs); // Output: 1678886400000

3. Using String Manipulation:

- You can convert the timestamp to a string and then use string manipulation to remove the milliseconds. This method is less efficient but can be useful in specific scenarios.

- Example:

const timestampWithMs = 1678886400123;
const timestampString = String(timestampWithMs);
const timestampWithoutMs = Number(timestampString.slice(0, -3) + '000');
console.log(timestampWithoutMs); // Output: 1678886400000

4. Using the `Date` Object:

- You can create a `Date` object from the timestamp and then get the timestamp without milliseconds using `getTime()`. This method is useful if you need to perform other date-related operations.

- Example:

const timestampWithMs = 1678886400123;
const date = new Date(timestampWithMs);
const timestampWithoutMs = date.getTime();
const timestampWithoutMsRounded = Math.floor(timestampWithoutMs / 1000) 1000;
console.log(timestampWithoutMsRounded); // Output: 1678886400000

Recommendation:

- For most cases, using `Math.floor(timestamp / 1000) 1000` is the most efficient and straightforward method to remove milliseconds from a timestamp in JavaScript.

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