master cea0d61 4/9: Prefer format-time-string to current-time-string

[Paul Eggert]

branch: master
commit cea0d61a69ef443924fdd4e4c429d7103b4acb9a
Author: Paul Eggert <eggert@cs.ucla.edu>
Commit: Paul Eggert <eggert@cs.ucla.edu>

    Prefer format-time-string to current-time-string
    
    * lisp/arc-mode.el (archive-unixdate):
    * lisp/gnus/nnrss.el (nnrss-normalize-date):
    * lisp/tar-mode.el (tar-clip-time-string):
    Prefer format-time-string to reassembling current-time-string output.
---
 doc/lispref/os.texi |  2 +-
 lisp/arc-mode.el    |  8 ++------
 lisp/gnus/nnrss.el  | 16 ++++++++--------
 lisp/tar-mode.el    |  4 ++--
 4 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index b4efc44..e369618 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -1352,7 +1352,7 @@ may change as higher-resolution clocks become available.
 
 @cindex time value
   Function arguments, e.g., the @var{time} argument to
-@code{current-time-string}, accept a more-general @dfn{time value}
+@code{format-time-string}, accept a more-general @dfn{time value}
 format, which can be a Lisp timestamp, @code{nil} for the current
 time, a single floating-point number for seconds, or a list
 @code{(@var{high} @var{low} @var{micro})} or @code{(@var{high}
diff --git a/lisp/arc-mode.el b/lisp/arc-mode.el
index 1fd1d66..ece30fe 100644
--- a/lisp/arc-mode.el
+++ b/lisp/arc-mode.el
@@ -617,12 +617,8 @@ OLDMODE will be modified accordingly just like chmod(2) 
would have done."
 
 (defun archive-unixdate (low high)
   "Stringify Unix (LOW HIGH) date."
-  (let* ((time (list high low))
-        (str (current-time-string time)))
-    (format "%s-%s-%s"
-           (substring str 8 10)
-           (substring str 4 7)
-           (format-time-string "%Y" time))))
+  (let ((system-time-locale "C"))
+    (format-time-string "%e-%b-%Y" (list high low))))
 
 (defun archive-unixtime (low high)
   "Stringify Unix (LOW HIGH) time."
diff --git a/lisp/gnus/nnrss.el b/lisp/gnus/nnrss.el
index 0ac57e9..59a22f7 100644
--- a/lisp/gnus/nnrss.el
+++ b/lisp/gnus/nnrss.el
@@ -450,7 +450,7 @@ nnrss: %s: Not valid XML %s and libxml-parse-html-region 
doesn't work %s"
 This function handles the ISO 8601 date format described in
 URL `https://www.w3.org/TR/NOTE-datetime', and also the RFC 822 style
 which RSS 2.0 allows."
-  (let (case-fold-search vector year month day time zone cts given)
+  (let (case-fold-search vector year month day time zone given)
     (cond ((null date))                        ; do nothing for this case
          ;; if the date is just digits (unix time stamp):
          ((string-match "^[0-9]+$" date)
@@ -481,13 +481,13 @@ which RSS 2.0 allows."
                            0
                          (decoded-time-zone decoded))))))
     (if month
-       (progn
-         (setq cts (current-time-string (encode-time 0 0 0 day month year)))
-         (format "%s, %02d %s %04d %s%s"
-                 (substring cts 0 3) day (substring cts 4 7) year time
-                 (if zone
-                     (concat " " (format-time-string "%z" nil zone))
-                   "")))
+       (concat (let ((system-time-locale "C"))
+                 (format-time-string "%a, %d %b %Y "
+                                     (encode-time 0 0 0 day month year)))
+               time
+               (if zone
+                   (format-time-string " %z" nil zone)
+                 ""))
       (message-make-date given))))
 
 ;;; data functions
diff --git a/lisp/tar-mode.el b/lisp/tar-mode.el
index db65561..0ca26f7 100644
--- a/lisp/tar-mode.el
+++ b/lisp/tar-mode.el
@@ -467,8 +467,8 @@ checksum before doing the check."
 
 (defun tar-clip-time-string (time)
   (declare (obsolete format-time-string "27.1"))
-  (let ((str (current-time-string time)))
-    (concat " " (substring str 4 16) (format-time-string " %Y" time))))
+  (let ((system-time-locale "C"))
+    (format-time-string " %b %e %H:%M %Y" time)))
 
 (defun tar-grind-file-mode (mode)
   "Construct a `rw-r--r--' string indicating MODE.