indeed!

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;
+    }
+}