Hi Hari,
When you post code, you should use code tags .
You can do this by writing the word "CODE" inside square brackets at the beginning of the code, and at the end "/CODE", also inside square brackets and without quotes.

I didn't know you were running AIX, but it's OK. Unfortunately, I don't have an AIX box to test an equivalent command . But take a look at this post or this post and see if it helps. It looks like in AIX there is an istat command. Alternatively you can google something like "Linux stat equivalent in AIX" or the like.

As far as the date format is concerned, you can examine date's man page by typing in your terminal "man date" (without quotes) and choose the format that best suits your needs.

Let me explain further:

Code:

date +%s -d "24 hours ago"

When you run the date command (without options) you get something like:

Code:

gacanepa@Gabriel-PC ~ $ date
Sat Jul 13 21:52:20 WARST 2013

In date's man page for AIX you should find a list of format modifiers. For example, the

Code:

+%s

modifier tells date to convert its output (shown above) to the number of seconds ellapsed since January 1, 1970 (known as Unix epoch).
As to the -d option:

Code:

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

So what this does is:
Display Unix epoch for the current timestamp minus 24 hours.
I'm pretty sure that you can find an equivalent for AIX. The best of luck!