Hi Vandana,
Although you are able to define your own hierarchies, I don't see a standard option to load such a hierarchy. Contrary to normal characteristics, time characteristics cannot be defined as an Infoprovider. This is a prerequisite for loading hierarchy data using the 7.x data staging technology (with transformation and DTP).
I don't see a standard way to get around it. The limitation of a time characteristic is that it cannot be defined as an InfoProvider.
Last but not least, you might want to have a look at the following discussion in this area:
Best regards,
Sander