Microsoft Azure,Webjob, in which timezone a webjob runs if I schedule a webjob to run daily at specified time using cron expression

Based on the comments mentioned here, WebJobs run into the timezone configured for the WebApp where your WebJob is hosted. From this post:

Assuming you have not configured anything for the timezone, your cron job should use UTC which is the default timezone in Azure.

From Changing the server time zone on Azure Web Apps, you can specify the time zone you want your application to run in by making an application setting called WEBSITE_TIME_ZONE and set it to a proper value. From this blog post:

If your app is hosted as a Web App on the Azure App Service (formerly known as Azure Websites), until recently you were completely out of luck. However there is now an easy and supported way to change the time zone for your w3wp process (and any processes it spawns):

All you need to do is add an Application Setting (via the portal or the management APIs) called WEBSITE_TIME_ZONE and set that to the name of the time zone as defined in the Windows Registry under HKLM\Software\Microsoft\Windows Nt\CurrentVersion\Time Zones\ (for example, “AUS Eastern Standard Time”).