Time specifications: Allow specifying relative times

* org.el (org-parse-time-string): Allow strings supported by tags/properties
matcher (eg <now>, <yesterday>, <-7d>) if the time starts with < and ends
with >.  This means that e.g. in the clocktable parameters you can specify
:tstart "<-1w>" :tend "<now>".

TINYCHANGE

lisp/org.el

@@ -16019,16 +16019,19 @@ When SHOW-ALL is nil, only return the current occurrence of a time stamp."
 This should be a lot faster than the normal `parse-time-string'.
 If time is not given, defaults to 0:00.  However, with optional NODEFAULT,
 hour and minute fields will be nil if not given."
-  (if (string-match org-ts-regexp0 s)
-      (list 0
-	    (if (or (match-beginning 8) (not nodefault))
-		(string-to-number (or (match-string 8 s) "0")))
-	    (if (or (match-beginning 7) (not nodefault))
-		(string-to-number (or (match-string 7 s) "0")))
-	    (string-to-number (match-string 4 s))
-	    (string-to-number (match-string 3 s))
-	    (string-to-number (match-string 2 s))
-	    nil nil nil)
+  (cond
+   ((string-match "^<.+>$" s)
+    (decode-time (seconds-to-time (org-matcher-time s))))
+   ((string-match org-ts-regexp0 s)
+    (list 0
+	  (if (or (match-beginning 8) (not nodefault))
+	      (string-to-number (or (match-string 8 s) "0")))
+	  (if (or (match-beginning 7) (not nodefault))
+	      (string-to-number (or (match-string 7 s) "0")))
+	  (string-to-number (match-string 4 s))
+	  (string-to-number (match-string 3 s))
+	  (string-to-number (match-string 2 s))
+	  nil nil nil))
     (error "Not a standard Org-mode time string: %s" s)))
 
 (defun org-timestamp-up (&optional arg)