So I'm using the RadScheduler control with WebApi and my appointment records come back from the server as iso 8601 strings like "2016-03-01T04:00:00Z". All dates that come from the server are in UTC format, and the RadScheduler control is set to render appointments using UTC time. So essentially if an appointment comes from the server as 8am UTC, then it should render at 8am on the scheduler, regardless of what timezone the client computer is set to.
Now there's an edge case that breaks the rendering of appointments. During the first X hours of the first day of a month, if an appointment starts within the first X hours, the parsing for the start time string fails and the appointment does not show up on the scheduler. The value X is the absolute value of the timezone offset for the client machine. So for instance if the machine is set to -5 hours offset, then appointments within the first 5 hours will not show up.
I've narrowed down the problem to the fact that the Telerik.Web.UI.Scheduler.Rendering.parseISO8601 function does not return a valid Date object in this scenario. You should be able to replicate this easily by executing Telerik.Web.UI.Scheduler.Rendering.parseISO8601("2016-03-01T04:00:00Z") assuming you have the Telerik.Web.UI.Scheduler.Rendering namespace / class loaded. It will return an invalid date if the client timezone offset is -5 or greater (-6, -7, etc..).
Is this a known issue and is there a fix?
3 Answers, 1 is accepted
I have tested the issue locally but could not replicate it at my side. Would you please elaborate if it is replicated only with WabApi binding it is also observed with other client side binding and it can be replicated on some of our demos.
If it is only replicated with WebApi binding please share the exact steps to replicate it one page and with this sample.
Regards,
Plamen
Telerik
Rank 1
Greetings, I was able to replicate the bug for you in the attached web application (dropbox link at end of message), which uses WebApi binding like my main implementation does. In my example, the api returns an appointment for every hour on June 1st, 2016. However, the first X appointments do not render. For me I do not see the first 4 appointments because I'm in GMT - 4 (X=4). You might need to adjust your computer's time to be in a timezone behind GMT to see this bug.
Please take a look and let me know if you can provide a solution. Thanks!
https://www.dropbox.com/s/koe66s7s0gohg5n/scheduler%20bug.zip?dl=0
Thank you for your concern with Telerik controls. The issue seems like a bug in the control. You can log it in our feedback portal here.
Regards,
Plamen
Telerik