Set DateTime (utc) to listitem (CSOM, SP2013)

Question

How to set UTC timezone to a listitem's DateTime field without executing query each time?

This would be slow for many datetime fields and items:

var utc = DateTime.UtcNow;
var localTime = clientContext.Web.RegionalSettings.TimeZone.UTCToLocalTime(utc);
clientContext.ExecuteQuery(); // Slow!
listItem["DateTime"] = localTime.Value;

We are using SP2013

Answer 1

Actually you don't have to, time will be saved in Local time when adding list item, so you could just specify time value like this:

listItem["DateTime"] = utc;

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Another option would be to retrieve SharePoint time zone and explicitly convert time into Local time using .NET Framework capabilities when saving list item as demonstrated below.

//1.Retrieve SharePoint TimeZone
var spTimeZone = context.Web.RegionalSettings.TimeZone;
context.Load(spTimeZone);
context.ExecuteQuery();

//2.Resolve System.TimeZoneInfo from Microsoft.SharePoint.Client.TimeZone 
var fixedTimeZoneName = sptimeZone.Description.Replace("and", "&"); 
var timeZoneInfo = TimeZoneInfo.GetSystemTimeZones().FirstOrDefault(tz => tz.DisplayName == fixedTimeZoneName);

//3.Convert time
listItem["DateTime"] = TimeZoneInfo.ConvertTimeFromUtc(utc, timeZoneInfo); 

Answer 2

To get local time you can also you basic javascript Date functions.Try below:

var currentDate= new Date();
currentDate.toTimeString();//Result format: 01:59:36 GMT+0530 (India Standard Time)

Answer 3

Ensure that you have set the time zone for the specific web application where you host your list. If it's not set (blank), SharePoint will use UTC.

Answer 4

Sharepoint saves the DateTime in UTC, so in order to retrieve the desired value you should save DateTimeOffset.Now.