使用 javascript / jquery 以 12 小时格式添加小时数

Question

How we can add hours into 12hour format time using Javascript/JQuery?

Example:

Add 2 hour in 12:00 AM then result should be 02:00 AM
Add 8 hour in 09:00 PM then result should be 05:00 AM

Answer 1

The following function takes a string representing a time and an integer denoting the number of hours you want to add to that time. You can optionally pass an integer number of minutes as well. The result is a string formatted as 'h:mm xm'.

 function addTimeToString(timeString, addHours, addMinutes) { // The third argument is optional. if (addMinutes === undefined) { addMinutes = 0; } // Parse the time string. Extract hours, minutes, and am/pm. var match = /(\\d+):(\\d+)\\s+(\\w+)/.exec(timeString), hours = parseInt(match[1], 10) % 12, minutes = parseInt(match[2], 10), modifier = match[3].toLowerCase(); // Convert the given time into minutes. Add the desired amount. if (modifier[0] == 'p') { hours += 12; } var newMinutes = (hours + addHours) * 60 + minutes + addMinutes, newHours = Math.floor(newMinutes / 60) % 24; // Now figure out the components of the new date string. newMinutes %= 60; var newModifier = (newHours < 12 ? 'AM' : 'PM'), hours12 = (newHours < 12 ? newHours : newHours % 12); if (hours12 == 0) { hours12 = 12; } // Glue it all together. var minuteString = (newMinutes >= 10 ? '' : '0') + newMinutes; return hours12 + ':' + minuteString + ' ' + newModifier; } function test(timeString, addHours, addMinutes) { document.write(timeString + ' + ' + addHours + ' h ' + (addMinutes || 0) + ' m &rarr; ' + addTimeToString(timeString, addHours, addMinutes) + '<br>'); } test('11:30 AM', 1, 45); test('9:00 PM', 4); test('11:55 PM', 0, 5); // In five minutes it will be midnight: 12 am. test('12:00 AM', 0, 5); // Five minutes after midnight: 12:05 am. test('11:55 AM', 0, 5); // In five minutes it will be noon: 12 pm. test('12:00 PM', 0, 5); // Five minutes after noon: 12:05 pm.

Answer 2

 function formatTime(date) { var meridiem = 'AM', hours; // Add the hours date.setHours(date.getHours() + 2); hours = date.getHours(); if (hours >= 12) { meridiem = 'PM'; hours = hours % 2; } hours = (hours === 0) ? 12 : hours; return formatNumber(hours) + ':' + formatNumber(date.getMinutes()) + ' ' + meridiem; } function formatNumber(number) { return ('0' + number).slice(-2); } alert(formatTime(new Date()));

Answer 3

I've added a couple of methods to the Date prototype class.

 //Complete Solution Date.createDateFromTime = function(hours, minutes) { var date = new Date(); date.setTime(hours, minutes); return date; } Date.prototype.setTime = function(hours, minutes) { this.setHours(hours); this.setMinutes(minutes); return this.displayTime(); } Date.prototype.displayTime = function() { function addZero(number) { if (number < 10) { return "0" + number.toString(); } else { return number.toString(); } } var hours = this.getHours(); var minutes = this.getMinutes(); var am_pm = "AM"; if (hours >= 12) { am_pm = "PM" hours -= 12; } if (hours == 0) hours = 12; hours = addZero(hours); minutes = addZero(minutes); return hours + ":" + minutes + " " + am_pm; } Date.prototype.addHours = function(hours) { this.setHours(this.getHours() + hours); return this.getHours(); } //Examples date = Date.createDateFromTime(19, 20); console.log(date.displayTime()); // "07:20 PM" date.addHours(4); console.log(date.displayTime()); // "11:20 PM" date.addHours(5); console.log(date.displayTime()); // "04:20 AM"