diff --git a/site-lisp/db-org.el b/site-lisp/db-org.el
index 12c1985..41958c7 100644
--- a/site-lisp/db-org.el
+++ b/site-lisp/db-org.el
@@ -512,27 +512,24 @@ are equal return nil."
               (org-use-tag-inheritance nil)
               (org-agenda-prefix-format '((tags . "  ")))))))
 
-(defun db/org-add-clocking-time ()
-  "Add \"CLOCK:\" line to the task under point in the current org-mode file.
-
-Start and end time will be queried interactively."
-  (interactive)
-  ;; FIXME: make this function to take two optional arguments
+(defun db/org-add-clocking-time (starting-time ending-time)
+  "Add \"CLOCK:\" line to the task under point in the current org-mode file."
+  (interactive
+   (list (starting-time (org-read-date 4 'totime nil
+                                       "Start:" (current-time) nil t))
+         (ending-time (org-read-date 4 'totime nil
+                                     "End:" (current-time) nil t))))
   (if (not (eq major-mode 'org-mode))
       (user-error "Must be in org mode")
-    (let* ((starting-time (org-read-date 4 'totime nil
-                                         "Start:" (current-time) nil t))
-           (ending-time (org-read-date 4 'totime nil
-                                       "End:" (current-time) nil t)))
-      (save-mark-and-excursion
-       (org-clock-find-position nil)
-       (open-line 1)
-       (indent-according-to-mode)
-       (insert "CLOCK: ")
-       (org-insert-time-stamp starting-time t t)
-       (insert "--")
-       (org-insert-time-stamp ending-time t t)
-       (org-clock-update-time-maybe)))))
+    (save-mark-and-excursion
+     (org-clock-find-position nil)
+     (open-line 1)
+     (indent-according-to-mode)
+     (insert "CLOCK: ")
+     (org-insert-time-stamp starting-time t t)
+     (insert "--")
+     (org-insert-time-stamp ending-time t t)
+     (org-clock-update-time-maybe))))
 
 (bind-key "C-c C-x C-a" #'db/org-add-clocking-time org-mode-map)