Calculate date difference

Shell Programming and Scripting
1

Hi All

Can you please help me with UNIX script code that will work with ksh shell on UNIX server

My Requirement

Time1: 09/17/13101536

Time2: 09/16/13101536

I want to calculate the difference in minutes for the dates with format given above. I have a requirement to wait for 30 mins from the start of the job before taking the next action and in the mean time also check for existance of a trigger file if the file is present than I dont need to wait for 30 mins infact take the action immediately.

Thanks

2

What's your system? Date math is easy on some systems and extremely difficult on others.

3

Its an IBM AIX system

---------- Post updated at 03:29 PM ---------- Previous update was at 03:25 PM ----------

Hi I am using the following code it works but the problem is that it does not take into account the date it works fine if its just time difference calculation on a same date

 timediff=`awk -v "time=$stTime" -v "date=$(date +%H:%M:%S)" '
  function abs(x) {return x<0 ? -x : x}
  BEGIN {
    split(time, ary, /[:,]/); t_sec = 3600*ary[1] + 60*ary[2] + ary[3]
    split(date, ary, /:/);    d_sec = 3600*ary[1] + 60*ary[2] + ary[3]
    # output difference in minutes
    print abs(t_sec - d_sec)/60
  }
4

Date math is much less trivial than time math, and about your only standard option for it on AIX is perl:

#!/usr/bin/perl

use Time::Local;

my @TA1=split(/\//, shift);
my @TA2=split(/\//, shift);

for($N=6; $N>=0; $N-=2)
{
        @TA1[2+($N/2)]=substr(@TA1[2], $N, 2);
        @TA2[2+($N/2)]=substr(@TA2[2], $N, 2);
}

@TA1[7]=timelocal(@TA1[5], @TA1[4], @TA1[3], @TA1[1], @TA1[0], @TA1[2]);
@TA2[7]=timelocal(@TA2[5], @TA2[4], @TA2[3], @TA2[1], @TA2[0], @TA2[2]);

print @TA1[7] - @TA2[7], "\n";

$ ./tdiff.pl 09/17/13101536 09/16/13101536
86400

$
5

Thank you so much for the reply but I am seeing that it does not give correct answer when I use 24 hrs time format like

./tdiff.pl 09/16/13231530 09/17/13001530 -3600

I was expecting to get 60 as the answer

6

Difference is in seconds, so -3600 is -60 mins