Issue with formatting Date field value in Apex

Question

I have a date field in a custom object that stores the following:

2016-01-01 00:00:00

That is what SF tells me the field value contains, when I output it using System.debug() in my Apex code.

Datetime d = priceList.Campaign_Effective_Date_Start__c;
System.debug ('Campaign_Effective_Date_Start__c - d = ' + d);

I need to get a formatted version of this date as:

01/01/2016

I've tried several ways to format the date, but I always end up getting:

12/31/2015

I've read some postings that state that I need to adjust the date to take into account my time zone offset. I'm not sure I understand why, since I'm OK with the date as it is stored in the SF database. I don't have a need to adjust it to take into account my current time zone, which is EDT (or 'America/New_York').

Is there a way I get the original date in formatted correctly, without having to manipulate it based on my current time zone?

Answer 1

You need to calculate the offset of the time element of your Datetime object.

Note the second parameter is the Timezone id, not a SF id but a Timezone.getId()

public static Integer timeZoneOffset_hours(Date d, String timezoneId) {
    TimeZone tzSelected = TimeZone.getTimeZone(timezoneId);
    TimeZone tzGmt = TimeZone.getTimeZone('Greenwich Mean Time');

    Integer gmtOffset = tzGmt.getOffset(d);
    Integer selectedOffset = tzSelected.getOffset(d);
    Integer hours = (selectedOffset - gmtOffset) / 1000 / 60 / 60; 

    return hours;
}

Using this you can pass the date portion of your datetime object and the timezone you wish to convert to.

You can easily get the timezone id of the user to pass into the method:

UserInfo.getTimeZone().getId();

Then add the offset returned by the method to your datetime:

d.addHours(the offest);

Then format that value for the date.

Answer 2

Following Date functions will help you. Current Time displays in UTC time

Datetime currentTime = System.now();
Date currentDate = System.now().Date();

System.debug('current date=' + currentDate);
TimeZone tz = UserInfo.getTimeZone();
System.debug('Display name: ' + tz.getDisplayName());
System.debug('Current local time=' + currentTime.format('MM-dd-yyyy ') + ' ' 
  + currentTime.format('h:mm a'));

Use format function to display the datetime at current timezone.

USER_DEBUG|[2]|DEBUG|current time=2016-11-09 20:29:17
USER_DEBUG|[4]|DEBUG|Display name: Pacific Standard Time
USER_DEBUG|[6]|DEBUG|Current local time=11-09-2016  12:29 PM

Answer 3

This is what I came up with. It takes a Date input and returns it formatted in MM/dd/yyyy format.

public static String getFormattedDate(Date d) {
        String formattedDate = '';

        TimeZone tz = UserInfo.getTimeZone();

        Datetime dt = DateTime.newInstance(d.year(), d.month(), d.day(),0,0,0);

        Integer offset = tz.getOffset(dt);  System.debug('gmtOffset: ' + offset);
        Integer offsetHours = offset / 1000 / 60 / 60;

        if(offsetHours < 0 ) {
            dt.addHours(+(offsetHours));
        }

        formattedDate = dt.format('MM/dd/yyyy');

        return formattedDate;
    }