Date/Time parts to variable as integer

Shell Programming and Scripting
1

Hi Guys,
i guess there is a several ways to grub the strings from date and time
like THISMONTH='/bin/date +%m'
but the hard part is to add or sub that string to a variable

i tried to use let command

TWOMONTHSAGO=$THISMONTH

declare -i TWOMONTHSAGO

let TWOMONTHSAGO-=2

but there are errors , syntax is wrong or it try to add string to integer...

i tried TWOMONTHSAGO = TWOMONTHSAGO-2
i'm a programmer but i'm not familiar with the bash script

can anybody help?

2

You're making it too hard.

The date command you have (assuming you have GNU coreutils and dateutils) will do some arithmetic for you

Start here: Time / Date Commands

Keep going! Be sure to read your info or man page for the date command.
Specifically the option:

   -d, --date=STRING
              display time described by STRING, not 'now'