Thank you so much for your solution. By the way, I’m using a simulator ‘Proteus’ and it worked for me there. But I havent checked in the actual circuit. I’ll analyse and give you the details.
For me the alarm function works as well. I think you are not aware of how to set it. The actual principle behind it is the latching operation. Like the Spdt switch used, which is connected to port 1^2 of the AT89c51 should be grounded while setting the Alarm and Time. Also remember that, before you do this, you should keep the alarm button at on position, until the alarm has been set.
Once you release the alarm button, the display will show the timing setting..
Hope this works for you..
You may ask for any further doubts 