Rework date repeat to use custom multiple values handling, we can't have multiple repeating date elements or everything breaks.

Get date popup working in node author section and fix validation and form_set_value code to work right in Drupal 6.

Remove database timezone handling by rolling back to previous version that used offsets instead. Based on problems noted in #218479 and #220663, we cannot count on database timezone handling to be available in MYSQL or work consistently with the timezone names that PHP uses in POSTGRES, so trying to do timezone conversions in the database is not going to work.

Synch with D5.2 version.

Getting rid of offsets!! Alter query code to cast ISO and UNIX dates to native datetimes and do timezone conversion in the database. Much faster and more accurate.

This will mean this version of the code will not work for databases that are not able to do native timezone conversion, but even inexpensive shared hosts will probably have the MYSQL database timezone tables installed, and PostgreSQL has good timezone handling enabled by default.

The MYSQL timezone conversion code should be accurate, the PostgreSQL code looks right from the documentation but needs to be verified.

The offset fields can now be dropped from the Date fields since we only need the timezone name to do the conversion.

I probably missed some places that need to be adjusted for this change, but this should get most of the necessary fixes in place.

Add a combo field and alternate display option to show the value of multiple date values instead of repeating the teaser view.

Small tweaks to various themes.

Rework the method of storing exception dates in Date Repeat. Instead of previous method of a single date box and a formated table of exception dates with checkboxes to remove them, switch the the CCK style of adding as many blank boxes as needed for exceptions and removing them by wiping out the values. This can easily pick up the AHAH add more button in D6 for a nicer UI.

Also fix the handling of exception dates to make sure those dates actually do get omitted, and this now seems to be working.

More work on repeating date computations and their tests. Adding repeating dates to CCK date fields now seems to be working, at least for the tested scenarios.

More rework of the date repeat rrule calculations; move lots of the code into .inc files since these are used often so no reason to parse all that code on every page.

Require the UNTIL date for now to simplify getting this working. Add in error checking to be sure that value is set and add some documentation to the date_reapeat.inc file about how this is implemented in the Date module.