Factor out date-timestamp* calculations to org-store-link-props

* lisp/org.el (org-store-link-props): Rewrite function to get
  date-timestamp* calculations.
* lisp/org-gnus.el:
* lisp/org-mhe.el:
* lisp/org-rmail.el:
* contrib/lisp/org-mew.el:
* contrib/lisp/org-vm.el:
* contrib/lisp/org-wl.el: Remove date-timestamp* copy-paste.
* doc/org.texi: Fix `org-capture-templates' documentation.

contrib/lisp/org-mew.el

@@ -167,19 +167,10 @@ with \"t\" key."
 	       (from (mew-header-get-value "From:"))
 	       (to (mew-header-get-value "To:"))
 	       (date (mew-header-get-value "Date:"))
-	       (date-ts (and date (format-time-string
-				   (org-time-stamp-format t)
-				   (date-to-time date))))
-	       (date-ts-ia (and date (format-time-string
-				      (org-time-stamp-format t t)
-				      (date-to-time date))))
 	       (subject (mew-header-get-value "Subject:"))
 	       desc link)
-	  (org-store-link-props :type "mew" :from from :to to
+	  (org-store-link-props :type "mew" :from from :to to :date date
 				:subject subject :message-id message-id)
-	  (when date
-	    (org-add-link-props :date date :date-timestamp date-ts
-				:date-timestamp-inactive date-ts-ia))
 	  (setq message-id (org-remove-angle-brackets message-id))
 	  (setq desc (org-email-link-description))
 	  (setq link (concat "mew:" folder-name "#" message-id))

contrib/lisp/org-vm.el

@@ -77,12 +77,6 @@
              (message-id (vm-su-message-id message))
              (link-type (if (vm-imap-folder-p) "vm-imap" "vm"))
 	     (date (vm-get-header-contents message "Date"))
-	     (date-ts (and date (format-time-string
-				 (org-time-stamp-format t)
-				 (date-to-time date))))
-	     (date-ts-ia (and date (format-time-string
-				    (org-time-stamp-format t t)
-				    (date-to-time date))))
 	     folder desc link)
         (if (vm-imap-folder-p)
 	    (let ((spec (vm-imap-find-spec-for-buffer (current-buffer))))
@@ -95,10 +89,7 @@
                 (setq folder (replace-match "" t t folder)))))
         (setq message-id (org-remove-angle-brackets message-id))
 	(org-store-link-props :type link-type :from from :to to :subject subject
-			      :message-id message-id)
-	(when date
-	  (org-add-link-props :date date :date-timestamp date-ts
-			      :date-timestamp-inactive date-ts-ia))
+			      :message-id message-id :date date)
 	(setq desc (org-email-link-description))
 	(setq link (concat (concat link-type ":") folder "#" message-id))
 	(org-add-link-props :link link :description desc)

contrib/lisp/org-wl.el

@@ -198,12 +198,6 @@ ENTITY is a message entity."
 		 (xref (org-wl-message-field 'xref wl-message-entity))
 		 (subject (org-wl-message-field 'subject wl-message-entity))
 		 (date (org-wl-message-field 'date wl-message-entity))
-		 (date-ts (and date (format-time-string
-				     (org-time-stamp-format t)
-				     (date-to-time date))))
-		 (date-ts-ia (and date (format-time-string
-					(org-time-stamp-format t t)
-					(date-to-time date))))
 		 desc link)
 
 	    ;; remove text properties of subject string to avoid possible bug
@@ -243,9 +237,7 @@ ENTITY is a message entity."
 	      (setq desc (org-email-link-description))
 	      (setq link (concat "wl:" folder-name "#" message-id-no-brackets))
 	      (org-add-link-props :link link :description desc)))
-	    (when date
-	      (org-add-link-props :date date :date-timestamp date-ts
-				  :date-timestamp-inactive date-ts-ia))
+	    (org-add-link-props :date date)
 	    (or link xref)))))))
 
 (defun org-wl-open-nntp (path)

doc/org.texi

@@ -7303,8 +7303,8 @@ Link type                        |  Available keywords
 ---------------------------------+----------------------------------------------
 bbdb                             |  %:name %:company
 irc                              |  %:server %:port %:nick
-vm, vm-imap, wl, mh, mew, rmail  |  %:type %:subject %:message-id
-                                 |  %:from %:fromname %:fromaddress
+vm, vm-imap, wl, mh, mew, rmail, |  %:type %:subject %:message-id
+gnus                             |  %:from %:fromname %:fromaddress
                                  |  %:to   %:toname   %:toaddress
                                  |  %:date @r{(message date header field)}
                                  |  %:date-timestamp @r{(date as active timestamp)}

lisp/org-gnus.el

@@ -159,16 +159,6 @@ If `org-store-link' was called with a prefix arg the meaning of
 	   (from (mail-header-from header))
 	   (message-id (org-remove-angle-brackets (mail-header-id header)))
 	   (date (org-trim (mail-header-date header)))
-	   (date-ts (and date
-			 (ignore-errors
-			   (format-time-string
-			    (org-time-stamp-format t)
-			    (date-to-time date)))))
-	   (date-ts-ia (and date
-			    (ignore-errors
-			      (format-time-string
-			       (org-time-stamp-format t t)
-			       (date-to-time date)))))
 	   (subject (copy-sequence (mail-header-subject header)))
 	   (to (cdr (assq 'To (mail-header-extra header))))
 	   newsgroups x-no-archive desc link)
@@ -190,11 +180,8 @@ If `org-store-link' was called with a prefix arg the meaning of
 	(setq to (or to (gnus-fetch-original-field "To"))
 	      newsgroups (gnus-fetch-original-field "Newsgroups")
 	      x-no-archive (gnus-fetch-original-field "x-no-archive")))
-      (org-store-link-props :type "gnus" :from from :subject subject
+      (org-store-link-props :type "gnus" :from from :date date :subject subject
 			    :message-id message-id :group group :to to)
-      (when date
-	(org-add-link-props :date date :date-timestamp date-ts
-			    :date-timestamp-inactive date-ts-ia))
       (setq desc (org-email-link-description)
 	    link (org-gnus-article-link
 		  group	newsgroups message-id x-no-archive))

lisp/org-mhe.el

@@ -88,17 +88,9 @@ supported by MH-E."
 	     (message-id (org-mhe-get-header "Message-Id:"))
 	     (subject (org-mhe-get-header "Subject:"))
 	     (date (org-mhe-get-header "Date:"))
-	     (date-ts (and date (format-time-string
-				 (org-time-stamp-format t) (date-to-time date))))
-	     (date-ts-ia (and date (format-time-string
-				    (org-time-stamp-format t t)
-				    (date-to-time date))))
 	     link desc)
-	(org-store-link-props :type "mh" :from from :to to
+	(org-store-link-props :type "mh" :from from :to to :date date
 			      :subject subject :message-id message-id)
-	(when date
-	  (org-add-link-props :date date :date-timestamp date-ts
-			      :date-timestamp-inactive date-ts-ia))
 	(setq desc (org-email-link-description))
 	(setq link (concat "mhe:" (org-mhe-get-message-real-folder) "#"
 			   (org-remove-angle-brackets message-id)))

lisp/org-rmail.el

@@ -65,19 +65,10 @@
 	       (to (mail-fetch-field "to"))
 	       (subject (mail-fetch-field "subject"))
 	       (date (mail-fetch-field "date"))
-	       (date-ts (and date (format-time-string
-				   (org-time-stamp-format t)
-				   (date-to-time date))))
-	       (date-ts-ia (and date (format-time-string
-				      (org-time-stamp-format t t)
-				      (date-to-time date))))
 	       desc link)
 	  (org-store-link-props
-	   :type "rmail" :from from :to to
+	   :type "rmail" :from from :to to :date date
 	   :subject subject :message-id message-id)
-	  (when date
-	    (org-add-link-props :date date :date-timestamp date-ts
-				:date-timestamp-inactive date-ts-ia))
 	  (setq message-id (org-remove-angle-brackets message-id))
 	  (setq desc (org-email-link-description))
 	  (setq link (concat "rmail:" folder "#" message-id))

lisp/org.el

@@ -9922,16 +9922,24 @@ active region."
 	 (car org-stored-links))))))
 
 (defun org-store-link-props (&rest plist)
-  "Store link properties, extract names and addresses."
-  (let (x adr)
-    (when (setq x (plist-get plist :from))
-      (setq adr (mail-extract-address-components x))
+  "Store link properties, extract names, addresses and dates."
+  (when x
+    (let ((adr (mail-extract-address-components x)))
       (setq plist (plist-put plist :fromname (car adr)))
-      (setq plist (plist-put plist :fromaddress (nth 1 adr))))
-    (when (setq x (plist-get plist :to))
-      (setq adr (mail-extract-address-components x))
-      (setq plist (plist-put plist :toname (car adr)))
-      (setq plist (plist-put plist :toaddress (nth 1 adr)))))
+      (setq plist (plist-put plist :fromaddress (nth 1 adr)))))
+  (let ((x (plist-get plist :to)))
+    (when x
+      (let ((adr (mail-extract-address-components x)))
+	(setq plist (plist-put plist :toname (car adr)))
+	(setq plist (plist-put plist :toaddress (nth 1 adr))))))
+  (let ((x (ignore-errors (date-to-time (plist-get plist :date)))))
+    (when x
+      (setq plist (plist-put plist :date-timestamp
+			     (format-time-string
+			      (org-time-stamp-format t) x)))
+      (setq plist (plist-put plist :date-timestamp-inactive
+			     (format-time-string
+			      (org-time-stamp-format t t) x)))))
   (let ((from (plist-get plist :from))
 	(to (plist-get plist :to)))
     (when (and from to org-from-is-user-regexp)