Template variables used in pkBlog

The template variables below are used in the blog as published on Pogwatch. I'm not fond of date-pickers, so I use a text field and check for valid dates using PHP's strtotime() function. (NB this returns false rather than zero for an invalid date starting somewhere around PHP 5.2; this is the behaviour my code expects).

pwTags
Comma-delimited category tags for blog items
Input Type: Check Box
Input Option Values: MODx||computers||internet||life||misc
Widget: Delimited List
Delimiter: , (comma)
pkRichContent
Rich text input for body of item
Input Type: RichText
Default Value: [+newsBody+]
Widget: Rich Text
Width: 100%
Height: 300px
Editor: TinyMCE
pkDate
Manual date to attach to items
Input Type: Date
Widget: Unixtime
pkDateTo
Last date to display item (unpub_date is pkDateTo + 1 day)
Input Type: Date
Widget: Unixtime
pkPreviewFlag
Flag to mark draft items (needed only in blog post template)
Input Type: Check Box
Input Option Values: Preview==1