On Wed, Dec 05, 2007 at 09:15:35PM -0600, Mike Miller wrote:
> My brother's birthday is on November 22.  Once every 7 years, on average, 
> his birthday falls on Thanksgiving.  I was curious about when exactly that 
> would occur in the future so I did something like this in the bash shell 
> on a GNU system:
> 
> for year in $(seq 2008 2060) ; do date -d 11/22/$year | grep Thu ; done

Thu Nov 22 00:00:00 CST 2012
Thu Nov 22 00:00:00 CST 2018
Thu Nov 22 00:00:00 CST 2029
Thu Nov 22 00:00:00 CST 2035
Thu Nov 22 00:00:00 CST 2040
Thu Nov 22 00:00:00 CST 2046
Thu Nov 22 00:00:00 CST 2057

> And if you try it, you'll see what happens -- it fails starting in 2038.

Works fine here.

> It also fails if you go back before 1970.

$ for year in $(seq 1776 2060) ; do date -d 11/22/$year | grep Thu>
Thu Nov 22 00:00:00 CST 1781
Thu Nov 22 00:00:00 CST 1787
Thu Nov 22 00:00:00 CST 1792
Thu Nov 22 00:00:00 CST 1798
Thu Nov 22 00:00:00 CST 1804
Thu Nov 22 00:00:00 CST 1810
Thu Nov 22 00:00:00 CST 1821
Thu Nov 22 00:00:00 CST 1827
Thu Nov 22 00:00:00 CST 1832
Thu Nov 22 00:00:00 CST 1838
Thu Nov 22 00:00:00 CST 1849
Thu Nov 22 00:00:00 CST 1855
Thu Nov 22 00:00:00 CST 1860
Thu Nov 22 00:00:00 CST 1866
Thu Nov 22 00:00:00 CST 1877

No it doesn't fail!

> By the way, this method works for any range of years:
> 
> for year in $(seq 1960 2060) ; do cal 11 $year | egrep -B5 '^18 19 20 21 22' | grep November ; done
> 
> That is, it shows you every November for the given range of years where 
> the 22nd of the month falls on a Thursday.  Thanksgiving wasn't on the 
> fourth Thursday of November until the 1930s -- before that it was on the 
> final Thursday of the month and therefore would always have been on 11/29 
> instead of on 11/22.
> 
> Funny what you can do easily with these GNU programs, eh?

Mike,

Tell the U admins to install a more modern Linux distro.  And get
32 more bits and sprinkle them above the CPU - it works wonders 8^)
Just make sure they don't fall onto the motherboard, as they might
short something...

Cheers,
florin

-- 
Bruce Schneier expects the Spanish Inquisition.
      http://geekz.co.uk/schneierfacts/fact/163
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://mailman.mn-linux.org/pipermail/tclug-list/attachments/20071205/3711e723/attachment.pgp