diff --git a/include/wchar.h b/include/wchar.h
index c206ab0500f0..89867ac746cd 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -101,6 +101,7 @@ typedef	__wint_t	wint_t;
 #endif
 
 struct __sFILE;
+struct tm;
 
 __BEGIN_DECLS
 wint_t	btowc(int);
@@ -127,6 +128,8 @@ wchar_t	*wcschr(const wchar_t *, wchar_t);
 int	wcscmp(const wchar_t *, const wchar_t *);
 wchar_t	*wcscpy(wchar_t * __restrict, const wchar_t * __restrict);
 size_t	wcscspn(const wchar_t *, const wchar_t *);
+size_t	wcsftime(wchar_t * __restrict, size_t, const wchar_t * __restrict,
+	    const struct tm * __restrict);
 size_t	wcslcat(wchar_t *, const wchar_t *, size_t);
 size_t	wcslcpy(wchar_t *, const wchar_t *, size_t);
 size_t	wcslen(const wchar_t *);
diff --git a/lib/libc/locale/Makefile.inc b/lib/libc/locale/Makefile.inc
index f3f4644a85f9..fd7644690ff4 100644
--- a/lib/libc/locale/Makefile.inc
+++ b/lib/libc/locale/Makefile.inc
@@ -11,7 +11,8 @@ SRCS+=	big5.c btowc.c collate.c collcmp.c euc.c fix_grouping.c frune.c \
 	mbrtowc.c mbrune.c mbsinit.c mbsrtowcs.c mbtowc.c mbstowcs.c \
 	mskanji.c nl_langinfo.c nomacros.c none.c rune.c \
 	runetype.c setinvalidrune.c setlocale.c setrunelocale.c table.c \
-	tolower.c toupper.c utf2.c wcrtomb.c wcsrtombs.c wcstol.c wcstombs.c \
+	tolower.c toupper.c utf2.c wcrtomb.c wcsrtombs.c wcsftime.c wcstol.c \
+	wcstombs.c \
 	wcstoul.c wctob.c wctomb.c wctrans.c wctype.c wcwidth.c
 
 .if ${LIB} == "c"
@@ -22,7 +23,8 @@ MAN+=	btowc.3 \
 	mbsrtowcs.3 multibyte.3 \
 	nl_langinfo.3 \
 	rune.3 \
-	setlocale.3 toascii.3 tolower.3 toupper.3 towlower.3 wcrtomb.3 \
+	setlocale.3 toascii.3 tolower.3 toupper.3 towlower.3 wcsftime.3 \
+	wcrtomb.3 \
 	wcsrtombs.3 wcstol.3 \
 	wctrans.3 wctype.3 wcwidth.3
 MAN+=	euc.4 utf2.4
diff --git a/lib/libc/locale/wcsftime.3 b/lib/libc/locale/wcsftime.3
new file mode 100644
index 000000000000..3c434694362d
--- /dev/null
+++ b/lib/libc/locale/wcsftime.3
@@ -0,0 +1,61 @@
+.\" Copyright (c) 2002 Tim J. Robbins
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd September 8, 2002
+.Dt WCSFTIME 3
+.Os
+.Sh NAME
+.Nm wcsftime
+.Nd "convert date and time to a wide-character string"
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.In wchar.h
+.Ft size_t
+.Fn wcsftime "wchar_t * restrict wcs" "size_t maxsize" "const wchar_t * restrict format" "const struct tm * restrict timeptr"
+.Sh DESCRIPTION
+The
+.Fn wcsftime
+function is equivalent to the
+.Fn strftime
+function except for the types of its arguments.
+Refer to
+.Xr strftime 3
+for a detailed description.
+.Sh COMPATIBILITY
+Some early implementations of
+.Fn wcsftime
+had a format argument with type
+.Vt "const char *"
+instead of
+.Vt "const wchar_t *" .
+.Sh SEE ALSO
+.Xr strftime 3
+.Sh STANDARDS
+The
+.Fn wcsftime
+function conforms to
+.St -isoC-99 .
diff --git a/lib/libc/locale/wcsftime.c b/lib/libc/locale/wcsftime.c
new file mode 100644
index 000000000000..31a1c4c13ae5
--- /dev/null
+++ b/lib/libc/locale/wcsftime.c
@@ -0,0 +1,87 @@
+/*-
+ * Copyright (c) 2002 Tim J. Robbins
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <limits.h>
+#include <stdlib.h>
+#include <time.h>
+#include <wchar.h>
+
+/*
+ * Convert date and time to a wide-character string.
+ *
+ * This is the wide-character counterpart of strftime(). So that we do not
+ * have to duplicate the code of strftime(), we convert the format string to
+ * multibyte, call strftime(), then convert the result back into wide
+ * characters.
+ *
+ * This technique loses in the presence of stateful multibyte encoding if any
+ * of the conversions in the format string change conversion state. When
+ * stateful encoding is implemented, we will need to reset the state between
+ * format specifications in the format string.
+ */
+size_t
+wcsftime(wchar_t * __restrict wcs, size_t maxsize,
+    const wchar_t * __restrict format, const struct tm * __restrict timeptr)
+{
+	static const mbstate_t initial;
+	mbstate_t state;
+	char *dst, *sformat;
+	size_t n, sflen;
+
+	/*
+	 * Convert the supplied format string to a multibyte representation
+	 * for strftime(), which only handles single-byte characters.
+	 */
+	state = initial;
+	sflen = wcsrtombs(NULL, &format, 0, &state);
+	if (sflen == (size_t)-1)
+		return (0);
+	sformat = alloca(sflen + 1);
+	state = initial;
+	wcsrtombs(sformat, &format, sflen + 1, &state);
+
+	/*
+	 * Allocate memory for longest multibyte sequence that will fit
+	 * into the caller's buffer and call strftime() to fill it.
+	 * Then, copy and convert the result back into wide characters in
+	 * the caller's buffer.
+	 */
+	if (SIZE_T_MAX / MB_CUR_MAX <= maxsize)
+		/* maxsize is prepostorously large - avoid int. overflow. */
+		return (0);
+	dst = alloca(maxsize * MB_CUR_MAX);
+	if (strftime(dst, maxsize, sformat, timeptr) == 0)
+		return (0);
+	state = initial;
+	n = mbsrtowcs(wcs, (const char **)&dst, maxsize, &state);
+	if (n == (size_t)-2 || n == (size_t)-1 || dst != NULL)
+		return (0);
+
+	return (n);
+}