Good.
How far have you got in this design?
What have you done so far?

The first thing to do at the start of any new Project is a review of The Literature - go to the library, and use internet search engines to find out the current "State of the Art"
(as the instructions said, you should've done that anyway before posting!)

The first step in the design must be to define exactly what it is you want your project to do.
For a digital clock, this must include:

* keeping time (ie, counting seconds, minutes, hours, etc)

* displaying the time

* a facility to set the time

You will also need a power supply, and you need to think about what you want it to do when the power fails.



Good - that covers the basic requirements.

First, you need the datasheets for all these parts.
You should also seek out the Support sections of the manufacturer's websites, and look for useful Application Notes, design examples, etc.

If you are not already familiar with the 8051, see the Standard Advice here:
http://www.8052.com/forum/read.phtml?id=66882
and look at the Tutorials on this site.

If you are not already familiar with your software tools, be sure to take time to gain that familiarity first:
http://www.8052.com/forum/read.phtml?id=67182

Now you need to take it a step at a time:
I recommend you start with the LCD - get that going first, then you will also be able to use it for debugging during the rest of the project.
There is an LCD tutorial on this site, and LCDs have been discussed plenty on this forum - use the 'Search' button.

Note: "LCD" = "Liquid Crystal Display" - so don't write "LCD display," because that's "Liquid Crystal Display display!"

Then you can move on to talking to the RTC, and then the "User Interface" for setting the time.

Once you've done the basics, you can think about adding extras like alarms, multiple timezones, etc, etc,...