diff --git a/cgit.h b/cgit.h
index 501cb48..5adef4d 100644
--- a/cgit.h
+++ b/cgit.h
@@ -32,8 +32,6 @@
 /*
  * Dateformats used on misc. pages
  */
-#define FMT_LONGDATE "%Y-%m-%d %H:%M:%S (%Z)"
-#define FMT_SHORTDATE "%Y-%m-%d"
 #define FMT_ATOMDATE "%Y-%m-%dT%H:%M:%SZ"
 
 
diff --git a/ui-commit.c b/ui-commit.c
index e697571..099d294 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -56,7 +56,7 @@ void cgit_print_commit(char *hex, const char *prefix)
 	cgit_close_filter(ctx.repo->email_filter);
 	html("</td><td class='right'>");
 	html_txt(show_date(info->author_date, info->author_tz,
-				cgit_date_mode(FMT_LONGDATE)));
+				cgit_date_mode(DATE_ISO8601)));
 	html("</td></tr>\n");
 	html("<tr><th>committer</th><td>");
 	cgit_open_filter(ctx.repo->email_filter, info->committer_email, "commit");
@@ -68,7 +68,7 @@ void cgit_print_commit(char *hex, const char *prefix)
 	cgit_close_filter(ctx.repo->email_filter);
 	html("</td><td class='right'>");
 	html_txt(show_date(info->committer_date, info->committer_tz,
-				cgit_date_mode(FMT_LONGDATE)));
+				cgit_date_mode(DATE_ISO8601)));
 	html("</td></tr>\n");
 	html("<tr><th>commit</th><td colspan='2' class='sha1'>");
 	tmp = oid_to_hex(&commit->object.oid);
diff --git a/ui-shared.c b/ui-shared.c
index d1f9249..03dcc08 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -607,11 +607,10 @@ void cgit_submodule_link(const char *class, char *path, const char *rev)
 		path[len - 1] = tail;
 }
 
-const struct date_mode *cgit_date_mode(const char *format)
+const struct date_mode *cgit_date_mode(enum date_mode_type type)
 {
 	static struct date_mode mode;
-	mode.type = DATE_STRFTIME;
-	mode.strftime_fmt = format;
+	mode.type = type;
 	mode.local = ctx.cfg.local_time;
 	return &mode;
 }
@@ -620,7 +619,7 @@ static void print_rel_date(time_t t, int tz, double value,
 	const char *class, const char *suffix)
 {
 	htmlf("<span class='%s' title='", class);
-	html_attr(show_date(t, tz, cgit_date_mode(FMT_LONGDATE)));
+	html_attr(show_date(t, tz, cgit_date_mode(DATE_ISO8601)));
 	htmlf("'>%.0f %s</span>", value, suffix);
 }
 
@@ -637,9 +636,9 @@ void cgit_print_age(time_t t, int tz, time_t max_relative)
 
 	if (secs > max_relative && max_relative >= 0) {
 		html("<span title='");
-		html_attr(show_date(t, tz, cgit_date_mode(FMT_LONGDATE)));
+		html_attr(show_date(t, tz, cgit_date_mode(DATE_ISO8601)));
 		html("'>");
-		html_txt(show_date(t, tz, cgit_date_mode(FMT_SHORTDATE)));
+		html_txt(show_date(t, tz, cgit_date_mode(DATE_SHORT)));
 		html("</span>");
 		return;
 	}
@@ -781,7 +780,7 @@ void cgit_print_docend(void)
 	else {
 		htmlf("<div class='footer'>generated by <a href='http://git.zx2c4.com/cgit/about/'>cgit %s</a> at ",
 			cgit_version);
-		html_txt(show_date(time(NULL), 0, cgit_date_mode(FMT_LONGDATE)));
+		html_txt(show_date(time(NULL), 0, cgit_date_mode(DATE_ISO8601)));
 		html("</div>\n");
 	}
 	html("</div> <!-- id=cgit -->\n");
diff --git a/ui-shared.h b/ui-shared.h
index 43789de..b457c97 100644
--- a/ui-shared.h
+++ b/ui-shared.h
@@ -61,7 +61,7 @@ __attribute__((format (printf,1,2)))
 extern void cgit_print_error(const char *fmt, ...);
 __attribute__((format (printf,1,0)))
 extern void cgit_vprint_error(const char *fmt, va_list ap);
-extern const struct date_mode *cgit_date_mode(const char *format);
+extern const struct date_mode *cgit_date_mode(enum date_mode_type type);
 extern void cgit_print_age(time_t t, int tz, time_t max_relative);
 extern void cgit_print_http_headers(void);
 extern void cgit_redirect(const char *url, bool permanent);
diff --git a/ui-tag.c b/ui-tag.c
index b011198..6b838cb 100644
--- a/ui-tag.c
+++ b/ui-tag.c
@@ -77,7 +77,7 @@ void cgit_print_tag(char *revname)
 		if (info->tagger_date > 0) {
 			html("<tr><td>tag date</td><td>");
 			html_txt(show_date(info->tagger_date, info->tagger_tz,
-						cgit_date_mode(FMT_LONGDATE)));
+						cgit_date_mode(DATE_ISO8601)));
 			html("</td></tr>\n");
 		}
 		if (info->tagger) {