Javascript将时间字符串设置为日期对象

Question

Please see the below code;

var d = new Date();
var s = "01.00 AM";
d.setTime(s);

I know this code is wrong. Please give me the correct way to set the time. I have 12 hour time in string format in my hand.

The time will vary. Cannot know what will be the time earlier. Also it is 12 hour time. So it will be AM or PM

Answer 1

You can parse the time with a regex, and set the hours and minutes accordingly:

http://jsfiddle.net/54VkC/1/

var d = new Date(),
    s = "01.25 PM",
    parts = s.match(/(\d+)\.(\d+) (\w+)/),
    hours = /am/i.test(parts[3]) ? parseInt(parts[1], 10) : parseInt(parts[1], 10) + 12,
    minutes = parseInt(parts[2], 10);

d.setHours(hours);
d.setMinutes(minutes);

alert(d);

Edit 1: As jaisonDavis pointed out, the original code will not work for AM or PM for 12.XX, which was an oversight since I never use 12-hour format myself, thinking it started at 00.00 which was wrong.

The corrected code which handles these cases can be seen here:

http://jsfiddle.net/54VkC/93/

 var test, parts, hours, minutes, date, d = (new Date()).getTime(), tests = ['01.25 PM', '11.35 PM', '12.45 PM', '01.25 AM', '11.35 AM', '12.45 AM'], i = tests.length, timeReg = /(\d+)\.(\d+) (\w+)/; for(; i-- > 0;) { test = tests[i]; parts = test.match(timeReg); hours = /am/i.test(parts[3]) ? function(am) {return am < 12 ? am : 0}(parseInt(parts[1], 10)) : function(pm) {return pm < 12 ? pm + 12 : 12}(parseInt(parts[1], 10)); minutes = parseInt(parts[2], 10); date = new Date(d); date.setHours(hours); date.setMinutes(minutes); console.log(test + ' => ' + date); }

Answer 2

I'm late to the party, but I thought I'd share a funtion that doesn't use regex:

function setDateTime(date, time) {
    var index = time.indexOf("."); // replace with ":" for differently displayed time.
    var index2 = time.indexOf(" ");

    var hours = time.substring(0, index);
    var minutes = time.substring(index + 1, index2);

    var mer = time.substring(index2 + 1, time.length);
    if (mer == "PM"){
        hours = hours + 12;
    }


    date.setHours(hours);
    date.setMinutes(minutes);
    date.setSeconds("00");

    return date;
}

Answer 3

Using moment.js will be the easy solution.

const fullDate = new Date();
// fullDate = Tue Dec 12 2017 11:18:30 GMT+0530 (IST) {}
const time = '01.00 AM';
const d = moment(fullDate).format('L'); // d = "12/12/2017"
const date = moment(d +' '+ time).format();
// date = "2017-12-12T01:00:00+05:30"

If you want convert moment date to js date

const jsDate = moment(date).toDate();

Answer 4

function getCurrentDate() {
    var lDate = new Date();
    var lDay = lDate.getDate();
    var lMonth = lDate.getMonth() + 1;
    var lYear = lDate.getFullYear();

    if (lDay < 10) {
        lDay = '0' + lDay
    }

    if (lMonth < 10) {
        lMonth = '0' + lMonth
    }
    mCurrentDate = lYear + "-" + lMonth + "-" + lDay + "T00:00:00+05:30";
}

Answer 5

I added a few things as an improvement to the accepted answer by @thebreiflabb to suit my use case and thought i'd share.

if the regex is changed to timeReg = /(\d+)[\.|:](\d+)\s?(\w+)/; , it'll handle a few other common cases.

namely:

• using a colon instead of decimal point between hours and minutes
• allowing am/pm to immediately follow the time with no space

also, setting the seconds to 0 (since that was my main use case)

the resulting code would be:

var test, parts, hours, minutes, date,
    d = (new Date()).getTime(),
    tests = ['01.25 PM', '01:25pm', '1:25 PM', '11.35 PM', '12.45 PM', '01.25 AM', '11.35 AM', '12.45 AM'],
    i = tests.length,
    timeReg = /(\d+)[\.|:](\d+)\s?(\w+)/;

for(; i-- > 0;) {
    test = tests[i];

    parts = test.match(timeReg);

    hours = /am/i.test(parts[3]) ?
        function(am) {return am < 12 ? am : 0}(parseInt(parts[1], 10)) :
        function(pm) {return pm < 12 ? pm + 12 : 12}(parseInt(parts[1], 10));

    minutes = parseInt(parts[2], 10);

    date = new Date(d);

    date.setHours(hours);
    date.setMinutes(minutes);
    date.setSeconds(0);

    console.log(test + ' => ' + date);
}