Round time to the nearest Minute using JavaScript

Borislav Hadzhiev

Last updated: Jan 16, 2022

Photo from Unsplash

**To round time to the nearest minute:**

- Convert 1 minute to milliseconds.
- Divide the date's value in milliseconds by the result from the conversion.
- Pass the result to the
`Math.round()`

function. - Multiply by the number of milliseconds in 1 minute.

index.js

`function roundToNearestMinute(date = new Date()) { const minutes = 1; const ms = 1000 * 60 * minutes; // 👇️ replace Math.round with Math.ceil to always round UP return new Date(Math.round(date.getTime() / ms) * ms); } // 👇️ Thu Jan 13 2022 08:30:00 (seconds are 29) console.log(roundToNearestMinute(new Date(2022, 0, 13, 8, 30, 29))); // 👇️ Thu Jan 13 2022 08:31:00 (minutes are 30) console.log(roundToNearestMinute(new Date(2022, 0, 13, 8, 30, 30)));`

We used the
Date()
constructor when logging the examples to the console. The parameters we passed
are: `year`

, `month`

(January = 0, February = 1, etc), `day of month`

, `hours`

,
`minutes`

, `seconds`

.

We created a reusable function that rounds a date to the nearest minute.

The function takes a

`Date`

object as a parameter or uses the current date and time if no parameter is provided.If you always want to round up, replace the `Math.round()`

function with
`Math.ceil()`

.

The `ms`

variable stores the number of milliseconds there are in `1`

minute.

The getTime method returns the number of milliseconds since the Unix Epoch.

We divide the result by the number of milliseconds in `1`

minute and round to
the nearest integer using the
Math.round
function.

Here are some examples of how `Math.round`

works.

index.js

`console.log(Math.round(2.49)); // 👉️ 2 console.log(Math.round(2.5)); // 👉️ 3`

The function rounds the number up or down to the nearest integer.

If the number is positive and its fractional part is greater than or equal to

`0.5`

, it gets rounded to the next higher absolute value.If the number is positive and its fractional portion is less than `0.5`

, it gets
rounded to the lower absolute value.

If you always want to round up to the next minute, use the Math.ceil function instead.

index.js

`function roundToNearestMinute(date = new Date()) { const minutes = 1; const ms = 1000 * 60 * minutes; return new Date(Math.ceil(date.getTime() / ms) * ms); } // 👇️ Thu Jan 13 2022 08:31:00 (seconds are 29) console.log(roundToNearestMinute(new Date(2022, 0, 13, 8, 30, 29))); // 👇️ Thu Jan 13 2022 08:31:00 (minutes are 30) console.log(roundToNearestMinute(new Date(2022, 0, 13, 8, 30, 30)));`

The `Math.ceil`

function returns the smallest integer that is greater than or
equal to the provided number.

index.js

`console.log(Math.ceil(2.1)); // 👉️ 3 console.log(Math.ceil(2.0001)); // 👉️ 3`

In short, if there is anything after the decimal, the number will get rounded to the next integer, otherwise the number is returned.

The last step is to multiply the value from calling `Math.round`

or `Math.ceil`

with the number of milliseconds there are in a minute and pass the result to the
`Date()`

constructor.

The `roundToNearestMinute`

function returns a new `Date`

object rounding the
seconds to the nearest whole minute.