yes!

libsrc/rp6502/gettimezone.c

@@ -1,17 +0,0 @@
-#include <rp6502.h>
-#include <time.h>
-
-int clock_gettimezone (time_t time, clockid_t clock_id, struct _timezone* tz)
-{
-    int ax;
-    ria_set_ax (clock_id);
-    ria_push_long (time);
-    ax = ria_call_int (RIA_OP_CLOCK_GETTIMEZONE);
-    if (ax >= 0) {
-        char i;
-        for (i = 0; i < sizeof (struct _timezone); i++) {
-            ((char*)tz)[i] = ria_pop_char ();
-        }
-    }
-    return ax;
-}

libsrc/rp6502/localtime.s

@@ -0,0 +1,12 @@
+;
+; struct tm* __fastcall__ localtime (const time_t* timep);
+;
+
+        .export         _localtime
+
+        .import         __localtime
+
+
+;--------------------------------------------------------------------------
+
+_localtime = __localtime

libsrc/rp6502/localtime_.c

@@ -0,0 +1,31 @@
+#include <rp6502.h>
+#include <time.h>
+#include <stdbool.h>
+
+static bool tzset_set = false;
+
+struct tm* __fastcall__ _time_t_to_tm (const time_t t);
+
+struct tm* __fastcall__ _localtime (const time_t* timep)
+{
+    long time = *timep;
+    struct tm* tm;
+    ria_set_axsreg (*timep);
+    time += ria_call_long (RIA_OP_TZQUERY);
+    tm = _time_t_to_tm (time);
+    tm->tm_isdst = ria_pop_char ();
+    if (!tzset_set) { tzset (); }
+    return tm;
+}
+
+void tzset (void)
+{
+    int ax = ria_call_int (RIA_OP_TZSET);
+    if (ax >= 0) {
+        char i;
+        for (i = 0; i < sizeof (struct _timezone); i++) {
+            ((char*)&_tz)[i] = ria_pop_char ();
+        }
+        tzset_set = true;
+    }
+}

libsrc/rp6502/tzset_time.s

@@ -1,26 +0,0 @@
-; tzset_time.s
-;
-; This file is part of
-; cc65 - a freeware C compiler for 6502 based systems
-;
-; https://cc65.github.io
-;
-; See "LICENSE" file for legal information.
-;
-; void __fastcall__ tzset_time (time_t* time);
-;
-
-        .export         _tzset_time
-        .import         _clock_gettimezone, __tz
-        .import         pushax, ldax0sp, ldeaxi, pusheax, pusha, incsp2
-        .include        "time.inc"
-
-
-_tzset_time:
-        jsr     ldeaxi
-        jsr     pusheax
-        lda     #CLOCK_REALTIME
-        jsr     pusha
-        lda     #<(__tz)
-        ldx     #>(__tz)
-        jmp     _clock_gettimezone