Depending on how you name your packages and tasks, system variables PackageName and TaskName might help you. Otherwise, you could try storing some addition information external to your package with the PackageID or TaskID as the key.

You could also consider using the out of the box logging. This can log the start and end time of relevant tasks for you (i.e. no code to write to get information logged. This can be used to log the package name with its start/end time, task start/end time. All you need to do is to write reports against the log table.