Formatting Date in React Render

I am getting data from and api and directly mapping the array from the api to the render. The time from the api if in the following format 2024-05-15T01:00:00-04:00 is there a way to format the data in the jsx of the react render or do I have to process the array before I render it?


    return (
            <div>{location} Hourly Forecast</div>
             { => {
        return (
          <div key={index.number}>

I would like to format the time in the index.starttime but not sure it is possible I have searched but cant find anyone that has done this.


Depending on how the API responds, the way you process and format the data will vary. But with that format you can use string time formatting inside to maping, for example, as shown below. Also, there’s no need to return again inside of mapping.

  const formattedStartTime = index.startTime.toLocaleString('en-US', { hour: 'numeric', minute: 'numeric', hour12: true });

Also if you don’t want to specific time format just for take to hour you can use this method too:

const date = new Date(index.startTime);
const hour = date.getHours();

Here is the related documentation to find what format do you want. There is pleanty method in there, toLocaleString is quite enough.

Happy coding.

Thanks I should have been able to figure that out. I just did this because I just wanted the hour and am and pm:

{ => {

                    const date = new Date(index.startTime)
                    let hour = date.getHours();
                    let amPm = hour >= 12 ? 'pm' : 'am';
                    hour = hour % 12;
                    hour = hour ? hour : 12;
                    let time = hour + ' ' + amPm;
                    return (

                        <View key={index.number}>
                            <Image style={styles.image} src={index.icon}></Image>



Did you try toLocaleString formatter? I wrote with directly api respond, but it should take a Date object. You can make a 12-hour format like this:

const date = new Date(index.startTime); 
const formattedStartTime = date.toLocaleString('en-US', {  hour: 'numeric',  minute: 'numeric',  hour12: true});

Also, one more additional piece of info, the default settings of the toLocaleString formatter work with the local time zone if you want to display the time in the input’s time zone (‘…-04:00’) you should specify a static time zone. Furthermore, if your API input contains multiple time zones, you can take to timeZone option from api.

const date = new Date(index.startTime); 
const formattedStartTime = date.toLocaleString('en-US', {  hour: 'numeric',  minute: 'numeric',  hour12: true}); 
//this return 08:00 AM from my location

const formattedStartTime = date.toLocaleString('en-US', {timeZone: 'America/New_York', hour: 'numeric', minute: 'numeric', hour12: true}); 
//This will return with original timeZone 01:00 AM

But what if the API doesn’t provide time zone information and there are several time zones, and we want to show them in their original time zones? I found this solution for this:

const date = new Date(startTime);
const timeZoneMatch = startTime.match(/([+-]\d{2}:\d{2})$/);
const timeZone = timeZoneMatch ? `${timeZoneMatch[1]}` : 'UTC';

const formattedStartTime = date.toLocaleString('en-US', {
    timeZone: timeZone,
    hour: 'numeric',
    minute: 'numeric',
    hour12: true });

This always returns the original time zone, which is taken from the last part of the startTime input via a regex match.

Happy coding!