Need help, Every friday in a month

Shell Programming and Scripting
1

I am trying to write a script that shows every Friday in a month.
I used
cal $1 $2 | grep -v "^$" | awk '{print $6}'

It doesn't work for the frist week of Friday because calendar command output has some spaces in the first line and awk '{print $6}' doesn't work. Anybody help
me with this problem?

2

cal $1 $2 | awk 'NR >2 { print substr($0,16,2)}'

3

I couldn't get how this command works. Can you just explain it's function......

4

command
cal 12 2006
Note:The result has not aligned properly,check in your OS box.
EDIT -- It is aligned now because I added code tags and restored the original spacing of the output. -- Perderabo

   December 2006
 S  M Tu  W Th  F  S
                1  2
 3  4  5  6  7  8  9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31

the dates start from 3rd line,thats why he is omitting the first two lines by checking the condition line number greater than 2. NR >2

then starting from 3rd line get the starting character as 16 and number of characters as 2,as Friday dates starts from 16th character (fixed ).

Regards,
cskumar.