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Date manipulation: Difference between revisions

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Date manipulation (view source)

Revision as of 02:14, 8 January 2015

73 bytes removed ,  9 years ago
→‎{{header|JavaScript}} formatting. Changed alert() to console.log(). Modified to use indexOf() as polyfills exist for all browsers. Changed to use === as it is idiomatic and also faster.
(Nimrod -> Nim)
Line 818:
 
<lang JavaScript>function add12hours(dateString) {
}▼
// Get the parts of the date string▼
var parts = dateString.split(/\s+/);,▼
var date = parts[1];,▼
var month = parts[0];,▼
var year = parts[2];,▼
var time = parts[3];▼
 
var hr = Number(time.split(':')[0]);,▼
var min = Number(time.split(':')[1].replace(/\D/g,''));,▼
var ampm = time && time.match(/[a-z]+$/i)[0];,▼
var zone = parts[4].toUpperCase();▼
 
▲ // Get the parts of the date string
▲ var parts = dateString.split(/\s+/);
▲ var date = parts[1];
▲ var month = parts[0];
▲ var year = parts[2];
▲ var time = parts[3];
▲ var ampm = time && time.match(/[a-z]+$/i)[0];
▲ var hr = Number(time.split(':')[0]);
▲ var min = Number(time.split(':')[1].replace(/\D/g,''));
▲ var zone = parts[4].toUpperCase();
var months = ['January','February','March','April','May','June',
'July','August','September','October','November','December'];
var zones = {'EST': 300, 'AEST': -600}; // Minutes to add to zone time to get UTC
 
// Convert month name to number, zero indexed. Return if invalid month
month = months.indexOf(month);
// Could use indexOf but not supported widely
if (month === -1) { return; }
for (var i=0, iLen=months.length; i<iLen; i++) {
if (months[i] == month) {
month = i;
}
▲ }
if (typeof month != 'number') return; // Invalid month name provided
 
// ConvertAdd 12 hours toas specified. Add another 12 if pm for 24hr time
ifhr += (ampm && ampm.toLowerCase() === 'pm') {? 24 : 12
hr += 12;
}
 
// Add 12 hours to hours
hr += 12;
 
// Create a date object in local zone
var dlocalTime = new Date(year, month, date);
dlocalTime.setHours(hr, min, 0, 0);
 
// Adjust minutes for the time zones▼
d.setMinutes(d.getMinutes() + zones[zone] - d.getTimezoneOffset() );▼
 
▲ // Adjust localTime minutes for the time zones so it is now a local date
// d is now a local date representing the same moment as the
// representing the same moment as the source date plus 12 hours
▲ dlocalTime.setMinutes(dlocalTime.getMinutes() + zones[zone] - dlocalTime.getTimezoneOffset() );
return dlocalTime;
}
 
var inputDateString = 'March 7 2009 7:30pm EST';
 
console.log(
alert(
'Input: ' + inputDateString + '\n' +
'+12hrs in local time: ' + add12hours(inputDateString)
Anonymous user
Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/109926"