在JavaScript中将UTC时间转换为小时，分钟和AM / PM格式

Question

给定UTC时间，将其转换为小时，分钟和AM / PM（例如“ 3:30 PM”）格式的简单方法是什么？

Answer 1

<script type="text/javascript">
<!--

var a_p = "";
var d = new Date();

var curr_hour = d.getHours();

if (curr_hour < 12)
   {
   a_p = "AM";
   }
else
   {
   a_p = "PM";
   }
if (curr_hour == 0)
   {
   curr_hour = 12;
   }
if (curr_hour > 12)
   {
   curr_hour = curr_hour - 12;
   }

var curr_min = d.getMinutes();

document.write(curr_hour + " : " + curr_min + " " + a_p);

//-->
</script>

http://www.webdevelopersnotes.com/tips/html/formatting_time_using_javascript.php

Answer 2

Use the following function, you can change a utc time in any format:-

var  getDateString = function(date, format) {
            var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
            getPaddedComp = function(comp) {
                return ((parseInt(comp) < 10) ? ('0' + comp) : comp)
            },
            formattedDate = format,
            o = {
                "y+": date.getFullYear(), // year
                "M+": months[date.getMonth()], //month
                "d+": getPaddedComp(date.getDate()), //day
                "h+": getPaddedComp((date.getHours() > 12) ? date.getHours() % 12 : date.getHours()), //hour
                "m+": getPaddedComp(date.getMinutes()), //minute
                "s+": getPaddedComp(date.getSeconds()), //second
                "S+": getPaddedComp(date.getMilliseconds()), //millisecond,
                "t+": (date.getHours() >= 12) ? 'PM' : 'AM'
            };

            for (var k in o) {
                if (new RegExp("(" + k + ")").test(format)) {
                    formattedDate = formattedDate.replace(RegExp.$1, o[k]);
                }
            }
            return formattedDate;
        };

Now you can use it to format any date object like:-

 getDateString(new Date(), "h:m:s:t")

o/p: "01:34:22:AM"


 getDateString(new Date(), "y:M:d")
 o/p:- "2014:Jun:20"

 getDateString(new Date(), "y/M/d h:m:s:t")
 o/p:- "2014/Jun/20 01:34:22:AM"

Answer 3

// d = new Date(utc);
var hour = d.getHours() == 0 ? 12 : (d.getHours() > 12 ? d.getHours() - 12 : d.getHours());
var min = d.getMinutes() < 10 ? '0' + d.getMinutes() : d.getMinutes();
var ampm = d.getHours() < 12 ? 'AM' : 'PM';
var time = hour + ':' + min + ' ' + ampm;