As a general rule, when having to deal with datetimes and timezones, NEVER store a localtime. If you are going to have users / processing in multiple timezones, the sanest way to deal with everything is to store it ALL in UTC / GMT from the outset.

Storing UTC makes it trivial to display correct localised date-times in Perl / various web and other front ends / languages etc using standard libraries, and without adding the overhead of your own complex date-math for all accesses to the data.

As an aside, MySQL <= 4.1 is a PITA for saving UTC - all the time functions are localtime, and affected by the TZ of your mysql daemon.

Use this expression for a UTC now() in MySQL:

  update mytable
  set right_now=DATE_ADD('1970-01-01', INTERVAL UNIX_TIMESTAMP() SECON
+D)
[download]

To get correct localtimes in Perl / etc, just make sure that you set the TZ of the process handling the request, and the localtime functions will do the hard work for you.