Remove timezone conversion from the value of ui:inputDateTime

Question

I have a public community which means that guest users will be sharing the same guest user record (But not all users will be guest). I am trying to create a way to for them to enter a dateTime and send it back to the server. It looks like ui:inputDateTime automatically converts the selected dateTime using the timezone on the user record.

Example 1:

• User Time Zone (on Salesforce user record) = GMT

• <ui:inputDateTime>: user enters January 26 12:00 PM

• value =2017-01-26T12:00:00.000Z

Example 2:

• User Time Zone (on Salesforce user record) = EST
• <ui:inputDateTime> user enters January 26 12:00 PM
• value = 2017-01-26T17:00:00.000Z

As guest users will be sharing the same record , I am trying to use moment.js to convert the time to utc using the utc-offset of the browser.

 var dateTime=component.find("UIdateTimeCmp").get("v.value"); 

 var convertedNewTime = moment(dateTime).utc().format('YYYY-MM-DD HH:mm:ss');

This worked when I tried using lightning:input type="Datetime-local" but then I discovered IE and firefox don't support it so I am switching to ui:inputDateTime.

The "z" makes moment think that the time is already in GMT so there is no conversion. A workaround for this I came up with is that If I know the user is a guest user and I know that the guest user record has a GMT timezone, I found that I could slice the z before converting.

 var dateTime=component.find("UIdateTimeCmp").get("v.value"); 
 dateTime= dateTime.slice(0,-1);
 var convertedNewTime = moment(dateTime).utc().format('YYYY-MM-DD HH:mm:ss');

But then this messes things up for users who are not guest users and do not have the GMT timezone on their record.

//salesforce timezone = EST
//User enters 12:00 PM. (Utc time should be 17:00:00)

var dateTime=component.find("UIdateTimeCmp").get("v.value"); //2017-01-26T17:00:00.000Z
dateTime= dateTime.slice(0,-1); 
var convertedNewTime =  moment(dateTime).utc().format('YYYY-MM-DD HH:mm:ss'); // 2017-01-26T22:00:00

I need a way to get the actual value the user sees in the datepicker rather than the value converted to the user record's timezone, so that I can use moment.js to convert the value to the browser's utc-offset.

Answer 1

The Lightning Framework has a localization service that you can use in your JS to format date/time values which should be helpful to you with your issue.

// get currrent date/time and localize based on user's browser settings

var dateFormat = $A.get("$Locale.dateFormat");
var dateString = $A.localizationService.formatDateTime(new Date(), dateFormat);


// explicitly format date/time value

var dateFormat = "MMMM d, yyyy h:mm a";
var userLocaleLang = $A.get("$Locale.LangLocale");
return $A.localizationService.formatDateTime(date, dateFormat,userLocaleLang);