AppleScript and Date Value: Date of Current Date

According to the AppleScript Language Guide (p.44), a date value has the properties of "month", "weekday", and so on. One of these properties is "date" which is described as "a string that consists of the date portion of the date value, for example 'June 3, 1993'." Given this, why can we not get the date of (current date)?

Example:
the weekday of (current date)
--> Tuesday
the month of (current date)
--> January
the day of (current date)
--> 21
the date of (current date)
--> cannot get date of date "Tuesday, January 21, 1997 1:36:57 PM"
This is a known problem and was documented in the Language Guide Errata document which ships in the AppleScript product box. An the excerpt from the document includes the answer to your question as well as some information about the day property which was omitted.

AppleScript Language Guide Errata

Page 44

Date property replaced: The 'date' property for date-time values as described on page 44 of the AppleScript Language Guide has been replaced by two properties: 'date string' and 'time string'. Their behavior is as follows:

date string: This property returns the date portion of a date-time value as a string, formatted according to the Date & Time Control Panel. For example:
date string of date "Monday, January 3, 1994 2:35:00 PM"
--> "Monday, January 3, 1994"

time string: This property returns the time portion of a date-time value as a string, formatted according to the Date & Time Control Panel. For example:
time string of date "Monday, January 3, 1994 2:35:00 PM"
--> "2:35:00 PM"

Page 44

Day property omitted: The 'day' property for date-time values was omitted from page 44 of the AppleScript Language Guide. It's function is to return the day of the month as an integer, or allow the day of the month to be set for a date-time value. Examples:

day of date "Thursday, February 3, 1994 12:00:00 AM"
--> 3

set myDate to date "Thursday, February 3, 1994 12:00:00 AM"
set day of myDate to 17
myDate --> date "Thursday, February 17, 1994 12:00:00 AM"

If a value which is too large to fit into that particular month is assigned to a date-time value, the date will roll over into the next month:

set myDate to date "Thursday, February 3, 1994 12:00:00 AM"
set day of myDate to 37
myDate --> date "Wednesday, March 9, 1994 12:00:00 AM"
Published Date: Feb 18, 2012