diff -r 1e3977e029fd tools/ioemu/hw/mc146818rtc.c
--- a/tools/ioemu/hw/mc146818rtc.c	Mon May 08 19:21:41 2006 +0100
+++ b/tools/ioemu/hw/mc146818rtc.c	Wed May 10 15:33:56 2006 -0400
@@ -178,10 +178,27 @@ static inline int from_bcd(RTCState *s, 
     }
 }
 
+static void send_timeoffset_msg(time_t delta)
+{
+
+/* This routine is used to inform another entity that the
+   base time offset has changed. For instance, if you
+   were using xenstore, you might want to write to the store
+   at this point.  Or, you might use some other method.
+   Whatever you might chose, here's a hook point to implement it.
+
+   One item of note is that this delta is in addition to
+   any existing offset you might be already using. */
+
+    return;
+}
+
 static void rtc_set_time(RTCState *s)
 {
     struct tm *tm = &s->current_tm;
-
+    time_t before, after;
+    
+    before = mktime(tm);
     tm->tm_sec = from_bcd(s, s->cmos_data[RTC_SECONDS]);
     tm->tm_min = from_bcd(s, s->cmos_data[RTC_MINUTES]);
     tm->tm_hour = from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
@@ -193,6 +210,12 @@ static void rtc_set_time(RTCState *s)
     tm->tm_mday = from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
     tm->tm_mon = from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
     tm->tm_year = from_bcd(s, s->cmos_data[RTC_YEAR]) + 100;
+
+    /* Compute, and send, the additional time delta
+       We could compute the total time delta, but this is
+       sufficient, and simple. */
+    after = mktime(tm);
+    send_timeoffset_msg(after-before);
 }
 
 static void rtc_copy_date(RTCState *s)
diff -r 1e3977e029fd tools/ioemu/hw/pc.c
--- a/tools/ioemu/hw/pc.c	Mon May 08 19:21:41 2006 +0100
+++ b/tools/ioemu/hw/pc.c	Wed May 10 15:33:56 2006 -0400
@@ -118,7 +118,7 @@ static void cmos_init_hd(int type_ofs, i
 }
 
 /* hd_table must contain 4 block drivers */
-static void cmos_init(uint64_t ram_size, int boot_device, BlockDriverState **hd_table)
+static void cmos_init(uint64_t ram_size, int boot_device, BlockDriverState **hd_table, time_t timeoffset)
 {
     RTCState *s = rtc_state;
     int val;
@@ -129,6 +129,7 @@ static void cmos_init(uint64_t ram_size,
 
     /* set the CMOS date */
     time(&ti);
+    ti += timeoffset;
     if (rtc_utc)
         tm = gmtime(&ti);
     else
@@ -379,7 +380,7 @@ void pc_init(uint64_t ram_size, int vga_
 void pc_init(uint64_t ram_size, int vga_ram_size, int boot_device,
              DisplayState *ds, const char **fd_filename, int snapshot,
              const char *kernel_filename, const char *kernel_cmdline,
-             const char *initrd_filename)
+             const char *initrd_filename, time_t timeoffset)
 {
     char buf[1024];
     int ret, linux_boot, initrd_size, i, nb_nics1;
@@ -573,7 +574,7 @@ void pc_init(uint64_t ram_size, int vga_
 
     floppy_controller = fdctrl_init(6, 2, 0, 0x3f0, fd_table);
 
-    cmos_init(ram_size, boot_device, bs_table);
+    cmos_init(ram_size, boot_device, bs_table, timeoffset);
 
     /* must be done after all PCI devices are instanciated */
     /* XXX: should be done in the Bochs BIOS */
diff -r 1e3977e029fd tools/ioemu/vl.c
--- a/tools/ioemu/vl.c	Mon May 08 19:21:41 2006 +0100
+++ b/tools/ioemu/vl.c	Wed May 10 15:33:56 2006 -0400
@@ -155,6 +155,7 @@ void *vtop_table;
 void *vtop_table;
 unsigned long toptab;
 unsigned long vgaram_pages;
+time_t timeoffset = 0;
 
 /***********************************************************/
 /* x86 ISA bus support */
@@ -2255,9 +2256,10 @@ void help(void)
            "-s              wait gdb connection to port %d\n"
            "-p port         ioreq port for xen\n"
            "-d domain       domain that we're serving\n"
-           "-domain-namn    domain name that we're serving\n"
+           "-domain-name    domain name that we're serving\n"
            "-hdachs c,h,s   force hard disk 0 geometry (usually qemu can guess it)\n"
            "-L path         set the directory for the BIOS and VGA BIOS\n"
+	   "-timeoffset     time offset (in seconds) from local time (Xen)\n"
 #ifdef USE_CODE_COPY
            "-no-code-copy   disable code copy acceleration\n"
 #endif
@@ -2355,6 +2357,7 @@ enum {
     QEMU_OPTION_monitor,
     QEMU_OPTION_domainname,
     QEMU_OPTION_serial,
+    QEMU_OPTION_timeoffset,
     QEMU_OPTION_loadvm,
     QEMU_OPTION_full_screen,
     QEMU_OPTION_vgaacc,
@@ -2428,6 +2431,7 @@ const QEMUOption qemu_options[] = {
     { "std-vga", 0, QEMU_OPTION_std_vga },
     { "monitor", 1, QEMU_OPTION_monitor },
     { "domain-name", 1, QEMU_OPTION_domainname },
+    { "timeoffset", HAS_ARG, QEMU_OPTION_timeoffset },
     { "serial", 1, QEMU_OPTION_serial },
     { "loadvm", HAS_ARG, QEMU_OPTION_loadvm },
     { "full-screen", 0, QEMU_OPTION_full_screen },
@@ -3058,7 +3062,10 @@ int main(int argc, char **argv)
             case QEMU_OPTION_domainname:
                 strncat(domain_name, optarg, sizeof(domain_name) - 20);
                 break;
-
+	    case QEMU_OPTION_timeoffset:
+                timeoffset = strtol(optarg, NULL, 0);
+	    	break;
+ 
             }
         }
     }
@@ -3396,7 +3403,7 @@ int main(int argc, char **argv)
 #if defined(TARGET_I386)
     pc_init(ram_size, vga_ram_size, boot_device,
             ds, fd_filename, snapshot,
-            kernel_filename, kernel_cmdline, initrd_filename);
+            kernel_filename, kernel_cmdline, initrd_filename, timeoffset);
 #elif defined(TARGET_PPC)
     ppc_init(ram_size, vga_ram_size, boot_device,
             ds, fd_filename, snapshot,
diff -r 1e3977e029fd tools/ioemu/vl.h
--- a/tools/ioemu/vl.h	Mon May 08 19:21:41 2006 +0100
+++ b/tools/ioemu/vl.h	Wed May 10 15:33:56 2006 -0400
@@ -663,7 +663,7 @@ void pc_init(uint64_t ram_size, int vga_
 void pc_init(uint64_t ram_size, int vga_ram_size, int boot_device,
              DisplayState *ds, const char **fd_filename, int snapshot,
              const char *kernel_filename, const char *kernel_cmdline,
-             const char *initrd_filename);
+             const char *initrd_filename, time_t timeoffset);
 
 /* ppc.c */
 void ppc_init (int ram_size, int vga_ram_size, int boot_device,