Function: Helper function to convert hex encoded chars to ASCII.

Function: Given a date in the timezone of the site, returns that date in UTC.

Function: Given a date in UTC or GMT timezone, returns that date in the timezone of the site.

Function: Given an ISO 8601 timezone, returns its UTC offset in seconds.

Function: Given an ISO 8601 (Ymd\TH:i:sO) date, returns a MySQL DateTime (Y-m-d H:i:s) format used by post_date[_gmt].

Function: Strips out all characters that are not allowable in an email.

Function: Determines the difference between two timestamps.

Function: Generates an excerpt from the content, if needed.