>From ba4f38b8337c83330f303e10e3fbf1a251a58fea Mon Sep 17 00:00:00 2001
From: Jack Henahan <address@hidden>
Date: Sat, 20 Jan 2018 11:35:33 -0500
Subject: [PATCH] Set `untilnow` to use the year -50000, rather than the
 earliest representable date.

---
 lisp/org-clock.el | 42 +++++++-----------------------------------
 1 file changed, 7 insertions(+), 35 deletions(-)

diff --git a/lisp/org-clock.el b/lisp/org-clock.el
index 496c4310a..519b1563b 100644
--- a/lisp/org-clock.el
+++ b/lisp/org-clock.el
@@ -468,38 +468,6 @@ to add an effort property.")
 (defvar org-clock-stored-resume-clock nil
   "Clock to resume, saved by `org-clock-load'")
 
-(defconst org-clock--oldest-date
-  (let* ((dichotomy
-	  (lambda (min max pred)
-	    (if (funcall pred min) min
-	      (cl-incf min)
-	      (while (> (- max min) 1)
-		(let ((mean (+ (ash min -1) (ash max -1) (logand min max 1))))
-		  (if (funcall pred mean) (setq max mean) (setq min mean)))))
-	    max))
-	 (high
-	  (funcall dichotomy
-		   most-negative-fixnum
-		   0
-		   (lambda (m)
-                     ;; libc in macOS 10.6 hangs when decoding times
-                     ;; around year -2**31.  Limit `high' not to go
-                     ;; any earlier than that.
-                     (unless (and (eq system-type 'darwin)
-                                  (string-match-p
-                                   "10\\.6\\.[[:digit:]]"
-                                   (shell-command-to-string
-                                    "sw_vers -productVersion"))
-                                  (<= m -1034058203135))
-                       (ignore-errors (decode-time (list m 0)))))))
-	 (low
-	  (funcall dichotomy
-		   most-negative-fixnum
-		   0
-		   (lambda (m) (ignore-errors (decode-time (list high m)))))))
-    (list high low))
-  "Internal time for oldest date representable on the system.")
-
 ;;; The clock for measuring work time.
 
 (defvar org-mode-line-string "")
@@ -2260,7 +2228,7 @@ have priority."
     ;; Format start and end times according to AS-STRINGS.
     (let* ((start (pcase key
 		    (`interactive (org-read-date nil t nil "Range start? "))
-		    (`untilnow org-clock--oldest-date)
+		    (`untilnow nil)
 		    (_ (encode-time 0 m h d month y))))
 	   (end (pcase key
 		  (`interactive (org-read-date nil t nil "Range end? "))
@@ -2283,8 +2251,12 @@ have priority."
 	      (`interactive "(Range interactively set)")
 	      (`untilnow "now"))))
       (if (not as-strings) (list start end text)
-	(let ((f (cdr org-time-stamp-formats)))
-	  (list (format-time-string f start)
+	(let ((f (cdr org-time-stamp-formats))
+              (safe-start
+	       (if (not start)
+		   (encode-time 0 0 0 0 0 -50000)
+		 start)))
+	  (list (format-time-string f safe-start)
 		(format-time-string f end)
 		text))))))
 
-- 
2.15.1