topic Re: date string comparison ? in Operating System - HP-UX

date string comparison ?

Ian McClement_1 — Thu, 19 Dec 2002 15:20:48 GMT

Hi
I have two strings with date/times in them
eg. "12:25 12:00" and "12:26 11:00"
is there some form of unix command that will compare two date strings (not necessarily in above format) and give the time between them ?

Any help appreciated

Thanks
Ian

Re: date string comparison ?

Pete Randall — Thu, 19 Dec 2002 15:22:32 GMT

Ian,

Search the forums (using the search button on the top left of this page) for Clay's caljd.sh script. It's a wonderful thing and just what you're looking for.

Pete

Re: date string comparison ?

Pete Randall — Thu, 19 Dec 2002 15:25:35 GMT

You can find a copy in this post:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x026250011d20d6118ff40090279cd0f9,00.html

Pete

Re: date string comparison ?

Pete Randall — Thu, 19 Dec 2002 16:49:42 GMT

Sorry Ian, I thought Clay's date hammer would handle that but none of my searches turn up anything of the sort, which makes sense because it deals with Julian dates.

Pete

Re: date string comparison ?

Ian McClement_1 — Thu, 19 Dec 2002 16:53:54 GMT

not bad - but need it to include the time aswell
and give answer in minutes !!
pushing my luck ?

Re: date string comparison ?

john korterman — Thu, 19 Dec 2002 18:23:07 GMT

Hi Ian,
if nothing else works, you can try the attached, rather slow script. It can return the number of seconds elapsed since 00:00 Jan 1 of a specified year - and a specified date/time. The script takes seven parameters of which the first is the year on whose midnight Jan 1 the count starts. The remaining six parameters are the year, month, day, hour, minute, and seconds to count up to.
It may sound obscure, an example: show the number of seconds since 00:00 Jan 1 of 2002 and December 25 12:25 same year:

# ./return_seconds.sh 2002 2002 12 25 12 00 00
30974400

Another example:
# ./return_seconds.sh 2002 2002 12 26 11 00 00
31057200

The difference in seconds:
# echo 31057200 - 30974400|bc
82800

And turned into minutes:
# echo 82800 \/ 60|bc
1380

Is that what you want?

regards,
John K.

Re: date string comparison ?

Rick Garland — Sat, 21 Dec 2002 00:23:23 GMT

There is always perl.
You can do the math on the seconds since epoch then convert back to local time.