UNIX for Dummies Questions & Answers

Hi All,

Can you please let me know how to get the yesterday's date of the given date if the given date is Sunday?
I can't use GNU. I have the code to get the yesterday's date based on the system date.

Thanks

Can you tell us what Operating System you are using. Some have excellent date functions built in, if you know how to call them. Others less so, but there are ways around it.



Robin
Liverpool/Blackburn
UK

Take a look at this link. You might get some pointers.

explore these options...and add a if loop to check for the weekday

Code:

date '+%A'  #Prints whole weekday eg:Wednesday
date '+%u'  #Prints 1-7 (Mon to Sun)
date '+%w'  #Prints 0-7 (Sub to Mon)

We are using AIX. I have used Perderabo's datecalc. Was wondering is there any short code. For time being I 'm using database to get this going.

Thanks

With AIX, there is a neat trick with the time zone you can do.
Assuming you have this:-

Code:

$ echo $TZ
GMT0BST
$ date
Wed 15 May 12:04:36 2013

You can:-

Code:

$ TZ=GMT24BST
$ date
Wed 15 May 12:05:07 2013

You may have to work out how to slot the appropriate value into the TZ variable. On AIX you can actually push it beyond 24 hours, so if you want 5 days ago (24x5=120 hours) you can :-

Code:

$ TZ=GMT120BST
$ date
Sat 11 May 12:06:38 2013

You will need to substitute your time zone and include the offset, so if you are EST5EDT (as in the man page example) you would be best with:-

Code:

$ TZ=EST29EDT

to go back 24 hours.



Does that feature help?



Robin