Starting in 2007, Daylight Saving Time in the US starts a few weeks earlier and ends a few weeks later than it previously has. Are your Linux boxes ready? Instead of checking the latest patches, here's a much quicker test:

$ zdump -v EST5EDT | grep 2007
EST5EDT Sun Mar 11 06:59:59 2007 UTC = Sun Mar 11 01:59:59 2007 EST isdst=0 gmtoff=-18000
EST5EDT Sun Mar 11 07:00:00 2007 UTC = Sun Mar 11 03:00:00 2007 EDT isdst=1 gmtoff=-14400
EST5EDT Sun Nov 4 05:59:59 2007 UTC = Sun Nov 4 01:59:59 2007 EDT isdst=1 gmtoff=-14400
EST5EDT Sun Nov 4 06:00:00 2007 UTC = Sun Nov 4 01:00:00 2007 EST isdst=0 gmtoff=-18000


If the the transition between isdst=0 and isdst=1 doesn't happen on March 11, you need to get the latest timezone data from your distribution!

NOTE: zdump can be found in /usr/bin or /usr/sbin, depending on your distribution.