Compare dates

[BobRaney]

Hello,

How can I compare dates in a script?

If 07/21/04 > 07/20/04
then echo "greater"
else echo "not greater"
fi

Thanks
Raney

 

[iribach]

you cannot compare MMDDYYYY,
but YYYYMMDD vs YYYYMMDD
loock around, there are a lot of threads playing
with split&&formating strings, computing date...

echo 07/20/04|sed -e 's/\(.*\)\/\(.*\)\/\(.*\)/\3\1\2/'
will transform 07/20/04 to 040720
and 040720 is now comparable to 040728
BUT this assume the input is exactly xx/xx/xx
the sed works, what if input is: 1/1/2004 vs 12/31/04
so:
- carefully check the input
- translate it to comparable strings
- compare the values

 

[RodKnowlton]

For more advanced date manipulation, check out this thread, in which I posted KornShell functions for converting to and from Julian days (not to be confused with Julian dates, there's a link to an explanation).

Rod Knowlton
IBM Certified Advanced Technical Expert pSeries and AIX 5L

 

[mrn]

This has been answered a few times already see thread822-845095 it's worth having a look in the unix scripting forum as loads of these types of questions have already been asked

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant.