使用org-get-scheduled-time获取schedule time时的注意事项

当使用 org-get-scheduled-time 获取某个heading的 schedule time 时,请保证 SCHEDULED: xxxx 是放在标题的正下方第一行的位置上。

因为 org-get-scheduled-time 最终是通过 org-entry-properties 来获取属性值的(SCHEDULED,定义在 org-special-propereties 中，这些熟悉并不会放在properties drawer中，但依然是属性的一种).

而 org-entry-properties 中获取SCHEDULED的代码是下面这一段。

(when (or (not specific)
          (member specific '("CLOSED" "DEADLINE" "SCHEDULED")))
  (forward-line)
  (when (looking-at-p org-planning-line-re)
    (end-of-line)
    (let ((bol (line-beginning-position))
          ;; Backward compatibility: time keywords used to
          ;; be configurable (before 8.3).  Make sure we
          ;; get the correct keyword.
          (key-assoc `(("CLOSED" . ,org-closed-string)
                       ("DEADLINE" . ,org-deadline-string)
                       ("SCHEDULED" . ,org-scheduled-string))))
      (dolist (pair (if specific (list (assoc specific key-assoc))
                      key-assoc))
        (save-excursion
          (when (search-backward (cdr pair) bol t)
            (goto-char (match-end 0))
            (skip-chars-forward " \t")
            (and (looking-at org-ts-regexp-both)
                 (push (cons (car pair)
                             (match-string-no-properties 0))
                       props)))))))
  (when specific (throw 'exit props)))

注意看第三行和第四行

(forward-line)
(when (looking-at-p org-planning-line-re)
  .....)

是的，它要求标题的下一行匹配 org-planning-line-re 的正则表达式.

而 org-planning-line-re 的值为

org-planning-line-re is a variable defined in ‘org.el’.
Its value is "^[ 	]*\\(\\(?:CLOSED\\|DEADLINE\\|SCHEDULED\\):\\)"

  This variable may be risky if used as a file-local variable.

Documentation:
Matches a line with planning info.
Matched keyword is in group 1.

从上面可以看出，不仅仅是 scheduled-time，deadline-time和closed-time 也是一样的情况。