Add relative dates to :deadline and :scheduled

README.org

@@ -191,7 +191,7 @@ These selectors take one argument alone, or multiple arguments in a list.
 +  =:category= :: Group items that match any of the given categories.  Argument may be a string or list of strings.
 +  =:children= :: Select any item that has child entries.  Argument may be ~t~ to match if it has any children, ~nil~ to match if it has no children, ~todo~ to match if it has children with any to-do keywords, or a string to match if it has children with certain to-do keywords.  You might use this to select items that are project top-level headings.  Be aware that this may be very slow in non-daily/weekly agenda views because of its recursive nature.
 +  =:date= :: Group items that have a date associated. Argument can be =t= to match items with any date, =nil= to match items without a date, or =today= to match items with today’s date. The =ts-date= text-property is matched against.
-+  =:deadline= :: Group items that have a deadline. Argument can be ~t~ (to match items with any deadline), ~nil~ (to match items that have no deadline), ~past~ (to match items with a deadline in the past), ~today~ (to match items whose deadline is today), or ~future~ (to match items with a deadline in the future). Argument may also be given like ~before DATE~ or ~after DATE~ where DATE is a date string that ~org-time-string-to-absolute~ can process.
++  =:deadline= :: Group items that have a deadline. Argument can be ~t~ (to match items with any deadline), ~nil~ (to match items that have no deadline), ~past~ (to match items with a deadline in the past), ~today~ (to match items whose deadline is today), or ~future~ (to match items with a deadline in the future). Argument may also be given like ~before DATE~ or ~after DATE~ where DATE is a date string that ~org-read-date~ can process.
 +  =:effort<= :: Group items that are less than (or equal to) the given effort. Argument is a time-duration string, like ~5~ or ~0:05~ for 5 minutes.
 +  =:effort>= :: Group items that are higher than (or equal to) the given effort. Argument is a time-duration string, like ~5~ or ~0:05~ for 5 minutes.
 +  ~:file-path~ :: Group items whose buffers' filename paths match any of the given regular expressions.
@@ -205,7 +205,7 @@ These selectors take one argument alone, or multiple arguments in a list.
 +  =:priority<= :: Group items that are lower than the given priority, e.g. ~A~.
 +  =:priority<== :: Group items that are lower than or equal to the given priority, e.g. ~B~.
 +  =:regexp= :: Group items that match any of the given regular expressions.
-+  =:scheduled= :: Group items that are scheduled.  Argument can be ~t~ (to match items scheduled for any date), ~nil~ (to match items that are not schedule), ~past~ (to match items scheduled for the past), ~today~ (to match items scheduled for today), or ~future~ (to match items scheduled for the future).  Argument may also be given like ~before DATE~ or ~after DATE~ where DATE is a date string that ~org-time-string-to-absolute~ can process.
++  =:scheduled= :: Group items that are scheduled.  Argument can be ~t~ (to match items scheduled for any date), ~nil~ (to match items that are not schedule), ~past~ (to match items scheduled for the past), ~today~ (to match items scheduled for today), or ~future~ (to match items scheduled for the future).  Argument may also be given like ~before DATE~ or ~after DATE~ where DATE is a date string that ~org-read-date~ can process.
 +  =:tag= :: Group items that match any of the given tags.  Argument may be a string or list of strings.
 +  =:time-grid= :: Group items that appear on the time grid.
 +  =:todo= :: Group items that match any of the given TODO keywords.  Argument may be a string or list of strings, or ~t~ to match any keyword, or ~nil~ to match only non-todo items.

examples.org

@@ -237,6 +237,15 @@ Let's say it's approaching the start of a new school year, and you want to see a
 
 Of course, you could also write that as a standard agenda command with the  [[http://orgmode.org/worg/org-tutorials/advanced-searching.html][advanced searching syntax]], and it would execute faster.
 
+Perhaps you want to see all tasks due within the next two weeks? You can use relative date notation like this:
+
+#+BEGIN_SRC elisp :results none
+  (let ((org-super-agenda-groups
+         '((:deadline (before "+2w"))
+           (:discard (:anything t)))))
+    (org-todo-list))
+#+END_SRC
+
 What if you wanted to group tasks that are due before the end of the current month?  You could use something like this:
 
 #+BEGIN_SRC elisp

org-super-agenda.el

@@ -434,8 +434,7 @@ match items that have no deadline), `past` (to match items with a
 deadline in the past), `today' (to match items whose deadline is
 today), or `future' (to match items with a deadline in the
 future).  Argument may also be given like `before DATE' or `after
-DATE', where DATE is a date string that
-`org-time-string-to-absolute' can process."
+DATE', where DATE is a date string that `org-read-date' can process."
   :section-name (pcase (car args)
                   ('t "Deadline items")
                   ('nil "Items without deadlines")
@@ -450,7 +449,7 @@ DATE', where DATE is a date string that
                    (org-today))))
          (target-date (pcase (car args)
                         ((or 'before 'on 'after)
-                         (org-time-string-to-absolute (cadr args))))))
+                         (org-time-string-to-absolute (org-read-date nil nil (cadr args)))))))
   :test (org-super-agenda--when-with-marker-buffer (org-super-agenda--get-marker item)
           (let ((entry-time (org-entry-get (point) "DEADLINE")))
             (pcase (car args)
@@ -471,8 +470,7 @@ Argument can be `t' (to match items scheduled for any date),
 items scheduled for the past), `today' (to match items scheduled
 for today), or `future' (to match items scheduled for the
 future).  Argument may also be given like `before DATE' or `after
-DATE', where DATE is a date string that
-`org-time-string-to-absolute' can process."
+DATE', where DATE is a date string that `org-read-date' can process."
   :section-name (pcase (car args)
                   ('t "Scheduled items")
                   ('nil "Unscheduled items ")
@@ -487,7 +485,7 @@ DATE', where DATE is a date string that
                    (org-today))))
          (target-date (pcase (car args)
                         ((or 'before 'on 'after)
-                         (org-time-string-to-absolute (cadr args))))))
+                         (org-time-string-to-absolute (org-read-date nil nil (cadr args)))))))
   :test (org-super-agenda--when-with-marker-buffer (org-super-agenda--get-marker item)
           (let ((entry-time (org-entry-get (point) "SCHEDULED")))
             (pcase (car args)