Read value of a file, remove first 2 chars and put this value in a variable

Shell Programming and Scripting
1

Hi i have need of read a file value with cat command and remove first 2character for example cat /sys/class/rtc/day

0x12

Remove char

12

And put this value in a variable

is possible with a script thanks for help

2 
read VAR < /sys/class/rtc/day
VAR=${VAR:2}
3

Or

VAR=${VAR#??}
4

Or

IFS=x read dummy VAR < /sys/class/rtc/day
5

ok i try

---------- Post updated at 04:44 AM ---------- Previous update was at 02:56 AM ----------

i have a problem because i not have a file.
But i have a result of a command for example:

root@freescale ~$ i2cget -f -y 0 0x51 8
0x12

how can take this value?

thanks

6 
var=$(i2cget -f -y 0 0x51 8|cut -c 3-)
7

PROBABLY cut -c 2- ?