Gantt chart start time variation


Dear All,

we are having Gantt chart to display the records alone, we restricted edit for users and enabled only Download and view option.

we have date difference(Start time) for various location from actual date from Database

for example
Task Name Start Time Duration
change date 03 to 06 06-Dec-2017 0

also find in below attached image.

The problem is when user login from Indian time zone 06-Dec-2017 correct,but when user login from UK location its displaying like 07-Dec-2017.

is there any date adding is happening for different time zones?
please help me to resolve this.



It’s strange issue. As usual tasks’ dates don’t depend on time zone.
Could you please reproduce the issue in the snippet system to help us understand the cause of it?
And also please specify timezones which we should set to replicate the issue accurately.


The dates retrieving from Database is in correct.

as per the data 06-Dec-2017 should be display on chart, but for some timezone its displaying as 05-Dec-2017(06-Dec-2017 - 1).

find the below reference, i try to change my system timezone and results came like below

(UTC -01:00) - 05-Dec-2017
(UTC +00:00) - 05-Dec-2017
(UTC +01:00) - 06-Dec-2017(My server is hosted on this time zone)
(UTC +05:30) - 06-Dec-2017

is there any property that i need to add for Resolve this date difference?


Perhaps you have set the value of gantt.config.server_utc to true.

Here are demos with the difference

  • note the parsed date value.


I have a related issue.

My data json has
… ,“start_date”: “19-02-2019”,“duration”: 85,“workdays”: 61…

My gantt shows a correct end date of 14th May.
My lightbox says the end is 15th May.

The console hints at why:

start=Tue Feb 19 2019 00:00:00 GMT+0000 (Greenwich Mean Time)
end=Wed May 15 2019 00:00:00 GMT+0100 (British Summer Time)

Converting to utc gives the correct result
utcEndDate=Tue May 14 2019 23:00:00 GMT+0100 (British Summer Time)

How can I get the Lightbox to behave?


Hi @daver!

I’ve created a snippet with a task from your post Gantt chart start time variation

If I switch to your timezone, I can see that the start date of this task is 19th February 2019 00:00:00, and the end date is 15th May 2019 00:00:00

Do you see the same?
If so, it seems to be the expected values, the task ends at midnight at the start of 15th May, not including 15th May itself.
Do I understand you correctly, that you expect the end date of this task to be shown as 14th May in the lightbox, since it’s the last day task is being worked on?


Hi Dmitry,
Yes, I expected the lightbox to say 14th May.
You’ve kindly explained the situation in
I’ll try your solutions.
Thanks for responding.