You have opened the Process Development perspective in the SAP NetWeaverDeveloper Studio and have expanded your project in Project Explorer view.
You have created a task.
The expiration time indicates the time when the task expires, that means, when the task is of no interest anymore and is programmatically canceled.
By default the task has no expiration time. You can define a default expiration time by defining an offset related to the task activation time or by using an expression to evaluate absolute time of type xsd:dateTime. The task is cancelled when the expiration time is reached.
You have defined a default expiration time for the task.