The server is sending a string in this format: 18:00:00. This is a time-of-day value independent of any date. How to convert it to 6:00PM in Javascript? I could prepend today's date as a string to the value sent by the server and then parse the combined values and then try the .toTimeString() method of the Date object, but the format that time method emits is 24-hour time with a seconds chunk. I could write a function, but is there something built in?
Nothing built in, my solution would be as follows :
function tConvert (time) {
// Check correct time format and split into components
time = time.toString ().match (/^([01]\d|2[0-3])(:)([0-5]\d)(:[0-5]\d)?$/) || [time];
if (time.length > 1) { // If time format correct
time = time.slice (1); // Remove full string match value
time[5] = +time[0] < 12 ? 'AM' : 'PM'; // Set AM/PM
time[0] = +time[0] % 12 || 12; // Adjust hours
}
return time.join (''); // return adjusted time or original string
}
tConvert ('18:00:00');
This function uses a regular expression to validate the time string and to split it into its component parts. Note also that the seconds in the time may optionally be omitted. If a valid time was presented, it is adjusted by adding the AM/PM indication and adjusting the hours.
The return value is the adjusted time if a valid time was presented or the original string.
See jsFiddle : http://jsfiddle.net/ZDveb/
To get AM/PM, Check if the hour portion is less than 12, then it is AM, else PM.
To get the hour, do (hour % 12) || 12.
This should do it:
var timeString = "18:00:00";
var H = +timeString.substr(0, 2);
var h = H % 12 || 12;
var ampm = (H < 12 || H === 24) ? "AM" : "PM";
timeString = h + timeString.substr(2, 3) + ampm;
That assumes that AM times are formatted as, eg, 08:00:00. If they are formatted without the leading zero, you would have to test the position of the first colon:
var hourEnd = timeString.indexOf(":");
var H = +timeString.substr(0, hourEnd);
var h = H % 12 || 12;
var ampm = (H < 12 || H === 24) ? "AM" : "PM";
timeString = h + timeString.substr(hourEnd, 3) + ampm;
toLocaleTimeString() makes this very simple. There is no need to do this yourself. You'll be happier and live longer if you don't attack dates with string methods.
const timeString = '18:00:00'
// Append any date. Use your birthday.
const timeString12hr = new Date('1970-01-01T' + timeString + 'Z')
.toLocaleTimeString({},
{timeZone:'UTC',hour12:true,hour:'numeric',minute:'numeric'}
);
document.getElementById('myTime').innerText = timeString12hr<h1 id='myTime'></h1>Based on gilly3's answer.
If you want to convert:
08:00 to 08:00 AM
16:00 to 04:00 PM
Then this will work:
function tConv24(time24) {
var ts = time24;
var H = +ts.substr(0, 2);
var h = (H % 12) || 12;
h = (h < 10)?("0"+h):h; // leading 0 at the left for 1 digit hours
var ampm = H < 12 ? " AM" : " PM";
ts = h + ts.substr(2, 3) + ampm;
return ts;
};
Researching this same question I have come across several complicated, hard to understand solutions, and then it dawned on me: There is a very simple solution that doesn't rely on hard-to-read regular expressions or other complicated code. Unless I am missing something obvious, this is an extremely simple, easy to understand solution:
function timeTo12HrFormat(time)
{ // Take a time in 24 hour format and format it in 12 hour format
var time_part_array = time.split(":");
var ampm = 'AM';
if (time_part_array[0] >= 12) {
ampm = 'PM';
}
if (time_part_array[0] > 12) {
time_part_array[0] = time_part_array[0] - 12;
}
formatted_time = time_part_array[0] + ':' + time_part_array[1] + ':' + time_part_array[2] + ' ' + ampm;
return formatted_time;
}
var time = timeTo12HrFormat(18:00:00);
console.log(time); // 6:00:00 PM
Assuming you will get the date string in a proper format, I have a solution.
function parseDateTime(dt) {
var date = false;
if (dt) {
var c_date = new Date(dt);
var hrs = c_date.getHours();
var min = c_date.getMinutes();
if (isNaN(hrs) || isNaN(min) || c_date === "Invalid Date") {
return null;
}
var type = (hrs <= 12) ? " AM" : " PM";
date = ((+hrs % 12) || hrs) + ":" + min + type;
}
return date;
}
parseDateTime("2016-11-21 12:39:08");//"12:39 AM"
parseDateTime("2017-11-21 23:39:08");//"11:39 PM"
Make sure that your time is in this format HH:MM:SS(PM/AM)
function timeConversion(s) {
s = s.split(':');
var time = s[2];
if(time.charAt(2) === 'A' && parseInt(s[0]) == 12) s[0] = '00';
if(time.charAt(2) === 'P' && parseInt(s[0]) <12) s[0] = parseInt(s[0])+12;
if(s[0] >=24) s[0]-=24;
var x = time.split('').slice(0,2);
s[2] = x.join('');
console.log(s.join(':'));
}
Here's a few variations that will work.
const oneLiner = (hour = "00", min = "00", sec = "00") => `${(hour % 12) || 12}:${("0" + min).slice(-2)}:${sec} ${(hour < 12) ? 'am' : 'pm'}`
console.log('oneliner', oneLiner(..."13:05:12".split(":")))
const oneLinerWithObjectInput = ({hour = "00", min = "00", sec = "00"} = {}) => `${(hour % 12) || 12}:${("0" + min).slice(-2)}:${sec} ${(hour < 12) ? 'am' : 'pm'}`
console.log('onelinerWithObjectInput', oneLinerWithObjectInput({
hour: "13:05:12".split(":")[0],
min: "13:05:12".split(":")[1],
sec: "13:05:12".split(":")[2]
}))
const multiLineWithObjectInput = ({hour = "00", min = "00", sec = "00"} = {}) => {
const newHour = (hour % 12) || 12
, newMin = ("0" + min).slice(-2)
, ampm = (hour < 12) ? 'am' : 'pm'
return `${newHour}:${newMin}:${sec} ${ampm}`
}
console.log('multiLineWithObjectInput', multiLineWithObjectInput({
hour: "13:05:12".split(":")[0],
min: "13:05:12".split(":")[1],
sec: "13:05:12".split(":")[2]
}))Here's my way using if statements.
const converTime = (time) => {
let hour = (time.split(':'))[0]
let min = (time.split(':'))[1]
let part = hour > 12 ? 'pm' : 'am';
min = (min+'').length == 1 ? `0${min}` : min;
hour = hour > 12 ? hour - 12 : hour;
hour = (hour+'').length == 1 ? `0${hour}` : hour;
return (`${hour}:${min} ${part}`)
}
console.log(converTime('18:00:00'))
console.log(converTime('6:5:00'))This might help to format if you are using ES6.
Below code snippet will ignore the seconds. If you want to consider seconds you can add that as the first parameter.
const formatFrom24Hrsto12Hrs = (time, ignoreZero = true) => {
let [hours, minutes] = time.split(':')
let modifier = +hours < 12 ? 'am' : 'pm'
hours = +hours % 12 || 12
minutes = ignoreZero && +minutes === 0 ? '' : `:${minutes}`
return hours + minutes + modifier
}
Thanks to @HBP for paving the way here!
I found this to add a little flexibility to the solution.
The RegEx has been updated to accommodate times before noon.
This solution allows you to pass any string to it. As long as a valid time (in this format 18:00 || 18:00:00 || 3:00 || 3:00:00) is somewhere in that string, you're good to go.
Note: you can use just the militaryToTweleveHourConverter or take the guts out of the parseTime variable. However, I'm formatting a date from a database with date-fns then passing that formatted date to the converter.
Totally works. Hope this helps.
import dateFns from 'date-fns';
//* +---------------------------+
//* Format ex. Sat 1/1/18 1:00pm
//* +---------------------------+
const formatMonthDayYearTime = date =>
militaryToTweleveHourConverter(
dateFns.format(new Date(date), 'ddd M/DD/YY H:mm')
);
//* +-------------------------------+
//* Convert MILITARY TIME to 12 hour
//* +-------------------------------+
const militaryToTweleveHourConverter = time => {
const getTime = time.split(' ');
const parseTime = getTime.map(res => {
// Check for correct time format and split into components or return non-time units unaltered
let timeUnit = res
.toString()
.match(/^([\d]|[0-1]\d|2[0-3])(:)([0-5]\d)(:[0-5]\d)?$/) || [res];
console.log('timeUnit', timeUnit);
// If the time format is matched, it will break the components into an array
// ie. ["19:00", "19", ":", "00", undefined]
if (timeUnit.length > 1) {
// Remove full string match value
timeUnit = timeUnit.slice(1);
// Set am/pm and assign it to the last index in the array
timeUnit[5] = timeUnit[0] < 12 ? 'am' : 'pm';
// Adjust hours by subtracting 12 from anything greater than 12 and replace the value in the hours index
timeUnit[0] = timeUnit[0] % 12 || 12;
}
// return adjusted time or original string
return timeUnit.join('');
});
// Re-assemble the array pieces into a string
return parseTime.join(' ');
};
console.log(formatMonthDayYearTime('Sat 9/17/18 18:30'));
// console log returns the following
// Mon 9/17/18 6:30pm
console.log(militaryToTweleveHourConverter('18:30'));
// console log returns the following
// 6:30pm
console.log(militaryToTweleveHourConverter('18:30:09'));
// console log returns the following
// 6:30:09pm
console.log(militaryToTweleveHourConverter('8:30:09'));
// console log returns the following
// 8:30:09am
function timeformat(date1) {
var date=new Date(date1);
var month = date.toLocaleString('en-us', { month: 'long' });
var mdate =date.getDate();
var year =date.getFullYear();
var hours = date.getHours();
var minutes = date.getMinutes();
var ampm = hours >= 12 ? 'pm' : 'am';
hours = hours % 12;
hours = hours ? hours : 12; // the hour '0' should be '12'
minutes = minutes < 10 ? '0'+minutes : minutes;
var strTime = mdate+"-"+month+"-"+year+" "+hours + ':' + minutes + ' ' + ampm;
return strTime;
}
var ampm=timeformat("2019-01-11 12:26:43");
console.log(ampm);
Here the Function to Convert time into am or pm with Date,it may be help Someone.
来源：https://stackoverflow.com/questions/13898423/javascript-convert-24-hour-time-of-day-string-to-12-hour-time-with-am-pm-and-no