very strange apache time zone problem

[Michael Torrie]

On my server, php apps are reporting the timezone is switching back and
forth between -0600 and -0500.  Also all the log files (access_log, and
error_log) bounce back and forth between these two time zones.  This is
becoming a problem for one poorly written app that stores dates as a
unix timestamp as depending on the refresh of the page shows appoints an
hour off of the expected time.

As I said it's not just a php problem.  The access logs all show this
weirdness.  Has anyone seen this before?  I found one other person on
google who has reported this problem, but no one replied at all to his
queries.  Likely I won't either, owing to the rarity of this problem!