Following changes have been made to DTC as of *850425103:

1) Fixed bugs for leap-year and January-February transitions
2) Month and year displays speeded up by formatting whole week at
   a time, rather than 1 terminal write for each day; likewise
   unflagged days within a month are not re-addressed.
3) Months are now uniformly displayed centered, in mixed
   upper/lower-case; days are displayed right justified.
4) Day-of-week is shown for daily appointment display; current
   half-hour is highlighted in reverse video.  Today's date is
   highlighted in reverse-video for week, month and year displays
   (also blinks for year), and current-day (i.e., the day
   corresponding to D command) is underlined for week and month
   displays.
5) Week display now uses VT100 graphics mode to draw true boxes,
   rather than approximations with | and =; month display for
   current month uses double-width characters.
6) + and - commands now display the item they have moved to.
7) Purge command has been extended to support Unschedule (cancel)
   and eXchange (reschedule) commands.
8) Date/time string parsing has been thoroughly overhauled so that
   any reasonable character string will be interpreted reasonably,
   thus '1-feb' is this year, D 512 is same as 12-MAY-<this year>
|  (out-of-range values are now automatically limited).  '=' means
   same date, '*' means 8:00>5:00, and +/- may be used for date
   deltas.  Examples:
	X * +Y W
   reschedules everything for the current day to same day next
   year, and displays resulting week's summary, while
	X * +52W D
   reschedules everything for the current day to same day of week
   next year, and shows resulting day's schedule, and
	X 9>12 1>4
   reschedules morning appointments to the afternoon (no
   redisplay).
9) Default appointments file is SYS$LOGIN:DTC.DAT (standard login
|  directory, preferred over logical name ME:), F command with no
|  filename restores the default.  Format of this file has not
   changed (except that trailing blanks and NULs will be deleted
   by P/U/X commands):
 *	yymmddhhh Text    (last h is 0 or 3 for hour or half-hour)
   (ESC sequences manually inserted in "Text" display as expected)
   Files are now opened with LIST carriage-control (rather than
   FORTRAN carriage-control), so that VMS TYPE or PRINT commands
   will display them correctly.  The VMS command
	SORT filename ;    (";" separated from filename by space)
   will re-order the file if it has become unordered due to
   rescheduling or addition of appointments out of sequence.
|  Files are opened for APPEND only when appointments are added,
|  otherwise they are opened READONLY, so that group appointment
|  files may be referenced by indirection feature (no error is
|  indicated if appointments can not be added due to lack of WRITE
|  access to a file).

An unadvertised feature has been retained:  if a time string is
entered for a command that defaults to D, without a corresponding
appointment string, the cursor will be placed at the appropriate
point on the (empty) screen, displaying a BLOT (, ^Z) so that the
user may type his appointment directly.  Examples
	D 12:	or	EV	or	10>11:30
(the last will be replicated 3 times).

The program does >>> NOT <<< check that the user is on a VT100 or
equivalent.