UNIX for Dummies Questions & Answers

I'm using Kshell scripts cronjobs to logrolling my daily log files and I stamped the log file at the end of the day by date stamp i.e.: %d_%m_%y-LogFile.

but the 22_01_2001-LogFile as example contains 21st Jan data and I want to stamp the log file with previous day.

so I'm trying to subtract one day from the current day but it doesn't work.
like: date +%d-1_%m_%y or date expr +%d - 1 _%m_%y.
or setting the day in variable then subtract one.
like: set today=`/usr/bin/date +%d`
set yesterday=/usr/bin/expr $today - 1

so how can I manipulate the date using date command and subtract a day, week, or moth from the current day.

If you are using the GNU version of date, you can do something like:

/bin/date --date="yesterday"

to get yesterdays date. Grab it as part of sh-utils from http://www.gnu.org

but I'm using
SunOS 5.7
Solaris 2.7

can I do date manipulate on this OS?

Install GCC on one platform and use GCC to compile the GNU tools for the right OS. When I work at any site, I always install the GCC compiler and environment. To do this expands your world greatly and provides a cross platform code base for utilities.