diff --git a/sbin/mount_msdos/mount_msdos.8 b/sbin/mount_msdos/mount_msdos.8
index 66a13fcf7cb8..4792b47724ae 100644
--- a/sbin/mount_msdos/mount_msdos.8
+++ b/sbin/mount_msdos/mount_msdos.8
@@ -1,4 +1,4 @@
-.\" $NetBSD: mount_msdos.8,v 1.27 2003/08/02 11:43:21 jdolecek Exp $
+.\" $NetBSD: mount_msdos.8,v 1.28 2003/09/07 22:09:11 itojun Exp $
 .\"
 .\" Copyright (c) 1993, 1994 Christopher G. Demetriou
 .\" All rights reserved.
@@ -45,6 +45,7 @@
 .Op Fl g Ar gid
 .Op Fl m Ar mask
 .Op Fl M Ar mask
+.Op Fl t Ar gmtoff
 .Op Fl s
 .Op Fl l
 .Op Fl 9
@@ -113,6 +114,11 @@ in the file system. The value of
 is used if it is supplied and
 .Fl M
 is omitted. See description of previous option for details.
+.It Fl t Ar gmtoff
+Set the time zone offset (in seconds) from UTC to
+.Ar gmtoff ,
+with positive values indicating east of the Prime Meridian.
+If not set, the user's current time zone will be used.
 .It Fl s
 Force behaviour to
 ignore and not generate Win'95 long filenames.
diff --git a/sbin/mount_msdos/mount_msdos.c b/sbin/mount_msdos/mount_msdos.c
index 8eebe3322c46..0d14be365d6e 100644
--- a/sbin/mount_msdos/mount_msdos.c
+++ b/sbin/mount_msdos/mount_msdos.c
@@ -1,4 +1,4 @@
-/* $NetBSD: mount_msdos.c,v 1.30 2003/08/02 11:42:20 jdolecek Exp $ */
+/* $NetBSD: mount_msdos.c,v 1.31 2003/09/07 22:09:11 itojun Exp $ */
 
 /*
  * Copyright (c) 1994 Christopher G. Demetriou
@@ -36,7 +36,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: mount_msdos.c,v 1.30 2003/08/02 11:42:20 jdolecek Exp $");
+__RCSID("$NetBSD: mount_msdos.c,v 1.31 2003/09/07 22:09:11 itojun Exp $");
 #endif /* not lint */
 
 #include <sys/cdefs.h>
@@ -51,6 +51,7 @@ __RCSID("$NetBSD: mount_msdos.c,v 1.30 2003/08/02 11:42:20 jdolecek Exp $");
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 #include <unistd.h>
 #include <util.h>
 
@@ -87,13 +88,15 @@ mount_msdos(argc, argv)
 {
 	struct msdosfs_args args;
 	struct stat sb;
-	int c, mntflags, set_gid, set_uid, set_mask, set_dirmask;
+	int c, mntflags, set_gid, set_uid, set_mask, set_dirmask, set_gmtoff;
 	char *dev, *dir, ndir[MAXPATHLEN+1];
+	time_t now;
+	struct tm *tm;
 
-	mntflags = set_gid = set_uid = set_mask = set_dirmask = 0;
+	mntflags = set_gid = set_uid = set_mask = set_dirmask = set_gmtoff = 0;
 	(void)memset(&args, '\0', sizeof(args));
 
-	while ((c = getopt(argc, argv, "Gsl9u:g:m:M:o:")) != -1) {
+	while ((c = getopt(argc, argv, "Gsl9u:g:m:M:o:t:")) != -1) {
 		switch (c) {
 		case 'G':
 			args.flags |= MSDOSFSMNT_GEMDOSFS;
@@ -126,6 +129,10 @@ mount_msdos(argc, argv)
 		case 'o':
 			getmntopts(optarg, mopts, &mntflags, 0);
 			break;
+		case 't':
+			args.gmtoff = atoi(optarg);
+			set_gmtoff = 1;
+			break;
 		case '?':
 		default:
 			usage();
@@ -175,6 +182,14 @@ mount_msdos(argc, argv)
 				sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
 		}
 	}
+
+	if (!set_gmtoff) {
+		/* use user's time zone as default */
+		time(&now);
+		tm = localtime(&now);
+		args.gmtoff = tm->tm_gmtoff;
+
+	}
 	args.flags |= MSDOSFSMNT_VERSIONED;
 	args.version = MSDOSFSMNT_VERSION;
 
diff --git a/sys/fs/msdosfs/denode.h b/sys/fs/msdosfs/denode.h
index 1c4ad866ca9d..193f68556a8e 100644
--- a/sys/fs/msdosfs/denode.h
+++ b/sys/fs/msdosfs/denode.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: denode.h,v 1.3 2003/06/29 22:31:09 fvdl Exp $	*/
+/*	$NetBSD: denode.h,v 1.4 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -221,18 +221,18 @@ struct denode {
 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
 #define	DETOV(de)	((de)->de_vnode)
 
-#define	DETIMES(dep, acc, mod, cre) \
+#define	DETIMES(dep, acc, mod, cre, gmtoff) \
 	if ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) { \
 		(dep)->de_flag |= DE_MODIFIED; \
 		if ((dep)->de_flag & DE_UPDATE) { \
-			unix2dostime((mod), &(dep)->de_MDate, &(dep)->de_MTime, NULL); \
+			unix2dostime((mod), gmtoff, &(dep)->de_MDate, &(dep)->de_MTime, NULL); \
 			(dep)->de_Attributes |= ATTR_ARCHIVE; \
 		} \
 		if (!((dep)->de_pmp->pm_flags & MSDOSFSMNT_NOWIN95)) { \
 			if ((dep)->de_flag & DE_ACCESS) \
-				unix2dostime((acc), &(dep)->de_ADate, NULL, NULL); \
+				unix2dostime((acc), gmtoff, &(dep)->de_ADate, NULL, NULL); \
 			if ((dep)->de_flag & DE_CREATE) \
-				unix2dostime((cre), &(dep)->de_CDate, &(dep)->de_CTime, &(dep)->de_CHun); \
+				unix2dostime((cre), gmtoff, &(dep)->de_CDate, &(dep)->de_CTime, &(dep)->de_CHun); \
 		} \
 		(dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS); \
 	}
diff --git a/sys/fs/msdosfs/direntry.h b/sys/fs/msdosfs/direntry.h
index e68e7e861b0c..857fac0930ea 100644
--- a/sys/fs/msdosfs/direntry.h
+++ b/sys/fs/msdosfs/direntry.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: direntry.h,v 1.1 2002/12/26 12:31:33 jdolecek Exp $	*/
+/*	$NetBSD: direntry.h,v 1.2 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -119,9 +119,10 @@ struct winentry {
 #define DD_YEAR_SHIFT		9
 
 #ifdef _KERNEL
-void	unix2dostime __P((struct timespec *tsp, u_int16_t *ddp,
+void	unix2dostime __P((struct timespec *tsp, int gmtoff, u_int16_t *ddp,
 	    u_int16_t *dtp, u_int8_t *dhp));
-void	dos2unixtime __P((u_int dd, u_int dt, u_int dh, struct timespec *tsp));
+void	dos2unixtime __P((u_int dd, u_int dt, u_int dh, int gmtoff,
+	    struct timespec *tsp));
 int	dos2unixfn __P((u_char dn[11], u_char *un, int lower));
 int	unix2dosfn __P((const u_char *un, u_char dn[12], int unlen,
 	    u_int gen));
diff --git a/sys/fs/msdosfs/msdosfs_conv.c b/sys/fs/msdosfs/msdosfs_conv.c
index cf8bb7b62115..62eb8cc0d0bd 100644
--- a/sys/fs/msdosfs/msdosfs_conv.c
+++ b/sys/fs/msdosfs/msdosfs_conv.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: msdosfs_conv.c,v 1.1 2002/12/26 12:31:34 jdolecek Exp $	*/
+/*	$NetBSD: msdosfs_conv.c,v 1.2 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1995, 1997 Wolfgang Solfrank.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: msdosfs_conv.c,v 1.1 2002/12/26 12:31:34 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: msdosfs_conv.c,v 1.2 2003/09/07 22:09:11 itojun Exp $");
 
 /*
  * System include files.
@@ -96,8 +96,9 @@ u_short lastdtime;
  * file timestamps. The passed in unix time is assumed to be in GMT.
  */
 void
-unix2dostime(tsp, ddp, dtp, dhp)
+unix2dostime(tsp, gmtoff, ddp, dtp, dhp)
 	struct timespec *tsp;
+	int gmtoff;
 	u_int16_t *ddp;
 	u_int16_t *dtp;
 	u_int8_t *dhp;
@@ -113,8 +114,7 @@ unix2dostime(tsp, ddp, dtp, dhp)
 	 * If the time from the last conversion is the same as now, then
 	 * skip the computations and use the saved result.
 	 */
-	t = tsp->tv_sec - (rtc_offset * 60)
-	     /* +- daylight savings time correction */ ;
+	t = tsp->tv_sec + gmtoff; /* time zone correction */
 	t &= ~1;
 	if (lasttime != t) {
 		lasttime = t;
@@ -177,10 +177,11 @@ u_long lastseconds;
  * not be too efficient.
  */
 void
-dos2unixtime(dd, dt, dh, tsp)
+dos2unixtime(dd, dt, dh, gmtoff, tsp)
 	u_int dd;
 	u_int dt;
 	u_int dh;
+	int gmtoff;
 	struct timespec *tsp;
 {
 	u_long seconds;
@@ -227,8 +228,8 @@ dos2unixtime(dd, dt, dh, tsp)
 		days += ((dd & DD_DAY_MASK) >> DD_DAY_SHIFT) - 1;
 		lastseconds = (days * 24 * 60 * 60) + SECONDSTO1980;
 	}
-	tsp->tv_sec = seconds + lastseconds + (rtc_offset * 60)
-	     /* -+ daylight savings time correction */ ;
+	tsp->tv_sec = seconds + lastseconds;
+	tsp->tv_sec -= gmtoff;	/* time zone correction */
 	tsp->tv_nsec = (dh % 100) * 10000000;
 }
 
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index a7642214e0ae..cd406c55c5f4 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: msdosfs_vfsops.c,v 1.8 2003/08/02 11:41:21 jdolecek Exp $	*/
+/*	$NetBSD: msdosfs_vfsops.c,v 1.9 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.8 2003/08/02 11:41:21 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.9 2003/09/07 22:09:11 itojun Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_quota.h"
@@ -147,6 +147,7 @@ update_mp(mp, argp)
 	pmp->pm_uid = argp->uid;
 	pmp->pm_mask = argp->mask & ALLPERMS;
 	pmp->pm_dirmask = argp->dirmask & ALLPERMS;
+	pmp->pm_gmtoff = argp->gmtoff;
 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
 
 	/*
diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c
index 844afd8f4a31..19b445740f01 100644
--- a/sys/fs/msdosfs/msdosfs_vnops.c
+++ b/sys/fs/msdosfs/msdosfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: msdosfs_vnops.c,v 1.6 2003/08/02 11:41:21 jdolecek Exp $	*/
+/*	$NetBSD: msdosfs_vnops.c,v 1.7 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: msdosfs_vnops.c,v 1.6 2003/08/02 11:41:21 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: msdosfs_vnops.c,v 1.7 2003/09/07 22:09:11 itojun Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -156,7 +156,7 @@ msdosfs_create(v)
 	ndirent.de_pmp = pdep->de_pmp;
 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
 	TIMEVAL_TO_TIMESPEC(&time, &ts);
-	DETIMES(&ndirent, &ts, &ts, &ts);
+	DETIMES(&ndirent, &ts, &ts, &ts, pdep->de_pmp->pm_gmtoff);
 	if ((error = createde(&ndirent, pdep, &dep, cnp)) != 0)
 		goto bad;
 	if ((cnp->cn_flags & SAVESTART) == 0)
@@ -221,7 +221,7 @@ msdosfs_close(v)
 	simple_lock(&vp->v_interlock);
 	if (vp->v_usecount > 1) {
 		TIMEVAL_TO_TIMESPEC(&time, &ts);
-		DETIMES(dep, &ts, &ts, &ts);
+		DETIMES(dep, &ts, &ts, &ts, dep->de_pmp->pm_gmtoff);
 	}
 	simple_unlock(&vp->v_interlock);
 	return (0);
@@ -287,7 +287,7 @@ msdosfs_getattr(v)
 	u_long fileid;
 
 	TIMEVAL_TO_TIMESPEC(&time, &ts);
-	DETIMES(dep, &ts, &ts, &ts);
+	DETIMES(dep, &ts, &ts, &ts, pmp->pm_gmtoff);
 	vap->va_fsid = dep->de_dev;
 	/*
 	 * The following computation of the fileid must be the same as that
@@ -316,10 +316,13 @@ msdosfs_getattr(v)
 	vap->va_nlink = 1;
 	vap->va_rdev = 0;
 	vap->va_size = ap->a_vp->v_size;
-	dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
+	dos2unixtime(dep->de_MDate, dep->de_MTime, 0, pmp->pm_gmtoff,
+	    &vap->va_mtime);
 	if (dep->de_pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
-		dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
-		dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CHun, &vap->va_ctime);
+		dos2unixtime(dep->de_ADate, 0, 0, pmp->pm_gmtoff,
+		    &vap->va_atime);
+		dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CHun,
+		    pmp->pm_gmtoff, &vap->va_ctime);
 	} else {
 		vap->va_atime = vap->va_mtime;
 		vap->va_ctime = vap->va_mtime;
@@ -398,9 +401,9 @@ msdosfs_setattr(v)
 			return (error);
 		if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
 		    vap->va_atime.tv_sec != VNOVAL)
-			unix2dostime(&vap->va_atime, &dep->de_ADate, NULL, NULL);
+			unix2dostime(&vap->va_atime, pmp->pm_gmtoff, &dep->de_ADate, NULL, NULL);
 		if (vap->va_mtime.tv_sec != VNOVAL)
-			unix2dostime(&vap->va_mtime, &dep->de_MDate, &dep->de_MTime, NULL);
+			unix2dostime(&vap->va_mtime, pmp->pm_gmtoff, &dep->de_MDate, &dep->de_MTime, NULL);
 		dep->de_Attributes |= ATTR_ARCHIVE;
 		dep->de_flag |= DE_MODIFIED;
 		de_changed = 1;
@@ -707,7 +710,7 @@ msdosfs_update(v)
 	TIMEVAL_TO_TIMESPEC(&time, &ts);
 	DETIMES(dep,
 	    ap->a_access ? ap->a_access : &ts,
-	    ap->a_modify ? ap->a_modify : &ts, &ts);
+	    ap->a_modify ? ap->a_modify : &ts, &ts, dep->de_pmp->pm_gmtoff);
 	if ((dep->de_flag & DE_MODIFIED) == 0)
 		return (0);
 	dep->de_flag &= ~DE_MODIFIED;
@@ -1232,7 +1235,7 @@ msdosfs_mkdir(v)
 	ndirent.de_pmp = pmp;
 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
 	TIMEVAL_TO_TIMESPEC(&time, &ts);
-	DETIMES(&ndirent, &ts, &ts, &ts);
+	DETIMES(&ndirent, &ts, &ts, &ts, pmp->pm_gmtoff);
 
 	/*
 	 * Now fill the cluster with the "." and ".." entries. And write
diff --git a/sys/fs/msdosfs/msdosfsmount.h b/sys/fs/msdosfs/msdosfsmount.h
index 6c85223cd9c4..e1c6b57131d9 100644
--- a/sys/fs/msdosfs/msdosfsmount.h
+++ b/sys/fs/msdosfs/msdosfsmount.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: msdosfsmount.h,v 1.3 2003/08/02 11:41:21 jdolecek Exp $	*/
+/*	$NetBSD: msdosfsmount.h,v 1.4 2003/09/07 22:09:11 itojun Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -56,6 +56,7 @@ struct msdosfs_args {
 	uid_t	uid;		/* uid that owns msdosfs files */
 	gid_t	gid;		/* gid that owns msdosfs files */
 	mode_t  mask;		/* mask to be applied for msdosfs perms */
+	int	gmtoff;		/* offset from UTC in seconds */
 	int	flags;		/* see below */
 
 	/* Following items added after versioning support */
@@ -102,6 +103,7 @@ struct msdosfsmount {
 				   for files */
 	mode_t pm_dirmask;	/* mask to and with file protection bits
 				   for directories */
+	int pm_gmtoff;		/* offset from UTC in seconds */
 	struct vnode *pm_devvp;	/* vnode for block device mntd */
 	struct bpb50 pm_bpb;	/* BIOS parameter blk for this fs */
 	u_long pm_FATsecs;	/* actual number of fat sectors */