How to schedule your Ubuntu machine to automate Update Process

Ubuntu updates come almost everyday, sometimes if there is a big update, it might take a lot of bandwidth and your download usage which can be very irritating.A solution to this could be to have your updates downloaded and installed during the night or when your not infront of your pc, this can be pretty convenient and helpful especially with certain isp's like bsnl which gives free unlimited internet usage between 2 and 8 am.
One way to do this, is using crontab, where you create a crontask to start the update process at a specific time.In this example the update is scheduled to start at 2:15am.Here's how you go about doing it

Step 1 : Go to your Terminal(Applications->Accessories->Terminal) and type crontab -e .
Step 2 : Now add the following line to it
15 2 * * * (aptitude -y update && aptitude -y safe-upgrade)

NOTE:In this example it is 2:15am change the first 2 numbers as you wish.The safe-upgrade option is used in this case to avoid kernel updates.The -y is used to say yes to all questions
Step 3 : Press Ctrl + X and then press Y and close the terminal window
Step 4 : You should now have ubuntu automatically updating itself