[SerializableAttribute]
public class JobExecutionContextImpl : IJobExecutionContext

[SerializableAttribute]
public class JobExecutionContextImpl : IJobExecutionContext

The JobDataMap found on this object (via the MergedJobDataMap method) serves as a convenience - it is a merge of the JobDataMap found on the JobDetail and the one found on the ITrigger, with the value in the latter overriding any same-named values in the former. It is thus considered a 'best practice' that the Execute code of a Job retrieve data from the JobDataMap found on this object

NOTE: Do not expect value 'set' into this JobDataMap to somehow be set back onto a job's own JobDataMap.

IJobExecutionContext s are also returned from the GetCurrentlyExecutingJobs  method. These are the same instances as those past into the jobs that are currently executing within the scheduler. The exception to this is when your application is using Quartz remotely (i.e. via remoting or WCF) - in which case you get a clone of the IJobExecutionContexts, and their references to the IScheduler and IJob instances have been lost (a clone of the JobDetail is still available - just not a handle to the job instance that is running).