diff --git a/libc/Android.mk b/libc/Android.mk
index 8c2ebd6..bcf546f 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -554,6 +554,8 @@
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := $(call all-c-files-under,tzcode)
+# tzcode doesn't include wcsftime, so we use the OpenBSD one.
+LOCAL_SRC_FILES += upstream-openbsd/lib/libc/time/wcsftime.c
 
 LOCAL_CFLAGS := $(libc_common_cflags)
 # Don't use ridiculous amounts of stack.
@@ -569,7 +571,7 @@
 
 LOCAL_CONLYFLAGS := $(libc_common_conlyflags)
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
-LOCAL_C_INCLUDES := $(libc_common_c_includes)
+LOCAL_C_INCLUDES := $(libc_common_c_includes) $(LOCAL_PATH)/tzcode/
 LOCAL_MODULE := libc_tzcode
 LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
diff --git a/libc/bionic/wctype.cpp b/libc/bionic/wctype.cpp
index 4fd590a..33cacd1 100644
--- a/libc/bionic/wctype.cpp
+++ b/libc/bionic/wctype.cpp
@@ -84,8 +84,3 @@
 int wcwidth(wchar_t wc) {
   return (wc > 0);
 }
-
-// TODO: implement wcsftime.
-size_t wcsftime(wchar_t* wcs, size_t maxsize, const wchar_t* format,  const struct tm* timptr) {
-  abort();
-}
diff --git a/libc/upstream-openbsd/lib/libc/time/wcsftime.c b/libc/upstream-openbsd/lib/libc/time/wcsftime.c
new file mode 100644
index 0000000..5760493
--- /dev/null
+++ b/libc/upstream-openbsd/lib/libc/time/wcsftime.c
@@ -0,0 +1,575 @@
+/*	$OpenBSD: wcsftime.c,v 1.2 2013/01/20 20:29:02 millert Exp $ */
+#include "private.h"
+
+/*
+** Based on the UCB version with the ID appearing below.
+** This is ANSIish only when "multibyte character == plain character".
+**
+** Copyright (c) 1989, 1993
+**	The Regents of the University of California.  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.
+** 3. Neither the name of the University nor the names of its contributors
+**    may be used to endorse or promote products derived from this software
+**    without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 "tzfile.h"
+#include "fcntl.h"
+#include <locale.h>
+#include <wchar.h>
+
+struct lc_time_T {
+	const wchar_t *	mon[MONSPERYEAR];
+	const wchar_t *	month[MONSPERYEAR];
+	const wchar_t *	wday[DAYSPERWEEK];
+	const wchar_t *	weekday[DAYSPERWEEK];
+	const wchar_t *	X_fmt;
+	const wchar_t *	x_fmt;
+	const wchar_t *	c_fmt;
+	const wchar_t *	am;
+	const wchar_t *	pm;
+	const wchar_t *	date_fmt;
+};
+
+#define Locale	(&C_time_locale)
+
+static const struct lc_time_T	C_time_locale = {
+	{
+		L"Jan", L"Feb", L"Mar", L"Apr", L"May", L"Jun",
+		L"Jul", L"Aug", L"Sep", L"Oct", L"Nov", L"Dec"
+	}, {
+		L"January", L"February", L"March", L"April", L"May", L"June",
+		L"July", L"August", L"September", L"October", L"November", 
+		L"December"
+	}, {
+		L"Sun", L"Mon", L"Tue", L"Wed",
+		L"Thu", L"Fri", L"Sat"
+	}, {
+		L"Sunday", L"Monday", L"Tuesday", L"Wednesday",
+		L"Thursday", L"Friday", L"Saturday"
+	},
+
+	/* X_fmt */
+	L"%H:%M:%S",
+
+	/*
+	** x_fmt
+	** C99 requires this format.
+	** Using just numbers (as here) makes Quakers happier;
+	** it's also compatible with SVR4.
+	*/
+	L"%m/%d/%y",
+
+	/*
+	** c_fmt
+	** C99 requires this format.
+	** Previously this code used "%D %X", but we now conform to C99.
+	** Note that
+	**	"%a %b %d %H:%M:%S %Y"
+	** is used by Solaris 2.3.
+	*/
+	L"%a %b %e %T %Y",
+
+	/* am */
+	L"AM",
+
+	/* pm */
+	L"PM",
+
+	/* date_fmt */
+	L"%a %b %e %H:%M:%S %Z %Y"
+};
+
+#define UNKNOWN L"?"
+static wchar_t *	_add(const wchar_t *, wchar_t *, const wchar_t *);
+static wchar_t *	_sadd(const char *, wchar_t *, const wchar_t *);
+static wchar_t *	_conv(int, const wchar_t *, wchar_t *, const wchar_t *);
+static wchar_t *	_fmt(const wchar_t *, const struct tm *, wchar_t *, const wchar_t *,
+			int *);
+static wchar_t *	_yconv(int, int, int, int, wchar_t *, const wchar_t *);
+
+extern char *	tzname[];
+
+#ifndef YEAR_2000_NAME
+#define YEAR_2000_NAME	"CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
+#endif /* !defined YEAR_2000_NAME */
+
+#define IN_NONE	0
+#define IN_SOME	1
+#define IN_THIS	2
+#define IN_ALL	3
+
+size_t
+wcsftime(wchar_t *__restrict s, size_t maxsize, 
+    const wchar_t *__restrict format, const struct tm *__restrict t)
+{
+	wchar_t *p;
+	int	warn;
+
+	tzset();
+	warn = IN_NONE;
+	p = _fmt(((format == NULL) ? L"%c" : format), t, s, s + maxsize, &warn);
+#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
+	if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
+		(void) fprintf(stderr, "\n");
+		if (format == NULL)
+			(void) fprintf(stderr, "NULL strftime format ");
+		else	(void) fwprintf(stderr, "strftime format \"%ls\" ",
+				format);
+		(void) fprintf(stderr, "yields only two digits of years in ");
+		if (warn == IN_SOME)
+			(void) fprintf(stderr, "some locales");
+		else if (warn == IN_THIS)
+			(void) fprintf(stderr, "the current locale");
+		else	(void) fprintf(stderr, "all locales");
+		(void) fprintf(stderr, "\n");
+	}
+#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
+	if (p == s + maxsize) {
+		if (maxsize > 0)
+			s[maxsize - 1] = '\0';
+		return 0;
+	}
+	*p = L'\0';
+	return p - s;
+}
+
+static wchar_t *
+_fmt(const wchar_t *format, const struct tm *t, wchar_t *pt, 
+    const wchar_t *ptlim, int *warnp)
+{
+	for ( ; *format; ++format) {
+		if (*format != L'%') {
+			if (pt == ptlim)
+				break;
+			*pt++ = *format;
+			continue;
+		}
+label:
+		switch (*++format) {
+		case '\0':
+			--format;
+			break;
+		case 'A':
+			pt = _add((t->tm_wday < 0 ||
+				t->tm_wday >= DAYSPERWEEK) ?
+				UNKNOWN : Locale->weekday[t->tm_wday],
+				pt, ptlim);
+			continue;
+		case 'a':
+			pt = _add((t->tm_wday < 0 ||
+				t->tm_wday >= DAYSPERWEEK) ?
+				UNKNOWN : Locale->wday[t->tm_wday],
+				pt, ptlim);
+			continue;
+		case 'B':
+			pt = _add((t->tm_mon < 0 ||
+				t->tm_mon >= MONSPERYEAR) ?
+				UNKNOWN : Locale->month[t->tm_mon],
+				pt, ptlim);
+			continue;
+		case 'b':
+		case 'h':
+			pt = _add((t->tm_mon < 0 ||
+				t->tm_mon >= MONSPERYEAR) ?
+				UNKNOWN : Locale->mon[t->tm_mon],
+				pt, ptlim);
+			continue;
+		case 'C':
+			/*
+			** %C used to do a...
+			**	_fmt("%a %b %e %X %Y", t);
+			** ...whereas now POSIX 1003.2 calls for
+			** something completely different.
+			** (ado, 1993-05-24)
+			*/
+			pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
+				pt, ptlim);
+			continue;
+		case 'c':
+			{
+			int warn2 = IN_SOME;
+
+			pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
+			if (warn2 == IN_ALL)
+				warn2 = IN_THIS;
+			if (warn2 > *warnp)
+				*warnp = warn2;
+			}
+			continue;
+		case 'D':
+			pt = _fmt(L"%m/%d/%y", t, pt, ptlim, warnp);
+			continue;
+		case 'd':
+			pt = _conv(t->tm_mday, L"%02d", pt, ptlim);
+			continue;
+		case 'E':
+		case 'O':
+			/*
+			** C99 locale modifiers.
+			** The sequences
+			**	%Ec %EC %Ex %EX %Ey %EY
+			**	%Od %oe %OH %OI %Om %OM
+			**	%OS %Ou %OU %OV %Ow %OW %Oy
+			** are supposed to provide alternate
+			** representations.
+			*/
+			goto label;
+		case 'e':
+			pt = _conv(t->tm_mday, L"%2d", pt, ptlim);
+			continue;
+		case 'F':
+			pt = _fmt(L"%Y-%m-%d", t, pt, ptlim, warnp);
+			continue;
+		case 'H':
+			pt = _conv(t->tm_hour, L"%02d", pt, ptlim);
+			continue;
+		case 'I':
+			pt = _conv((t->tm_hour % 12) ?
+				(t->tm_hour % 12) : 12,
+				L"%02d", pt, ptlim);
+			continue;
+		case 'j':
+			pt = _conv(t->tm_yday + 1, L"%03d", pt, ptlim);
+			continue;
+		case 'k':
+			/*
+			** This used to be...
+			**	_conv(t->tm_hour % 12 ?
+			**		t->tm_hour % 12 : 12, 2, ' ');
+			** ...and has been changed to the below to
+			** match SunOS 4.1.1 and Arnold Robbins'
+			** strftime version 3.0. That is, "%k" and
+			** "%l" have been swapped.
+			** (ado, 1993-05-24)
+			*/
+			pt = _conv(t->tm_hour, L"%2d", pt, ptlim);
+			continue;
+		case 'l':
+			/*
+			** This used to be...
+			**	_conv(t->tm_hour, 2, ' ');
+			** ...and has been changed to the below to
+			** match SunOS 4.1.1 and Arnold Robbin's
+			** strftime version 3.0. That is, "%k" and
+			** "%l" have been swapped.
+			** (ado, 1993-05-24)
+			*/
+			pt = _conv((t->tm_hour % 12) ?
+				(t->tm_hour % 12) : 12,
+				L"%2d", pt, ptlim);
+			continue;
+		case 'M':
+			pt = _conv(t->tm_min, L"%02d", pt, ptlim);
+			continue;
+		case 'm':
+			pt = _conv(t->tm_mon + 1, L"%02d", pt, ptlim);
+			continue;
+		case 'n':
+			pt = _add(L"\n", pt, ptlim);
+			continue;
+		case 'p':
+			pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
+				Locale->pm :
+				Locale->am,
+				pt, ptlim);
+			continue;
+		case 'R':
+			pt = _fmt(L"%H:%M", t, pt, ptlim, warnp);
+			continue;
+		case 'r':
+			pt = _fmt(L"%I:%M:%S %p", t, pt, ptlim, warnp);
+			continue;
+		case 'S':
+			pt = _conv(t->tm_sec, L"%02d", pt, ptlim);
+			continue;
+		case 's':
+			{
+				struct tm	tm;
+				wchar_t		buf[INT_STRLEN_MAXIMUM(
+							time_t) + 1];
+				time_t		mkt;
+
+				tm = *t;
+				mkt = mktime(&tm);
+				if (TYPE_SIGNED(time_t))
+					(void) swprintf(buf, 
+					    sizeof buf/sizeof buf[0],
+					    L"%ld", (long) mkt);
+				else	
+					(void) swprintf(buf, 
+					    sizeof buf/sizeof buf[0],
+					    L"%lu", (unsigned long) mkt);
+				pt = _add(buf, pt, ptlim);
+			}
+			continue;
+		case 'T':
+			pt = _fmt(L"%H:%M:%S", t, pt, ptlim, warnp);
+			continue;
+		case 't':
+			pt = _add(L"\t", pt, ptlim);
+			continue;
+		case 'U':
+			pt = _conv((t->tm_yday + DAYSPERWEEK -
+				t->tm_wday) / DAYSPERWEEK,
+				L"%02d", pt, ptlim);
+			continue;
+		case 'u':
+			/*
+			** From Arnold Robbins' strftime version 3.0:
+			** "ISO 8601: Weekday as a decimal number
+			** [1 (Monday) - 7]"
+			** (ado, 1993-05-24)
+			*/
+			pt = _conv((t->tm_wday == 0) ?
+				DAYSPERWEEK : t->tm_wday,
+				L"%d", pt, ptlim);
+			continue;
+		case 'V':	/* ISO 8601 week number */
+		case 'G':	/* ISO 8601 year (four digits) */
+		case 'g':	/* ISO 8601 year (two digits) */
+/*
+** From Arnold Robbins' strftime version 3.0: "the week number of the
+** year (the first Monday as the first day of week 1) as a decimal number
+** (01-53)."
+** (ado, 1993-05-24)
+**
+** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
+** "Week 01 of a year is per definition the first week which has the
+** Thursday in this year, which is equivalent to the week which contains
+** the fourth day of January. In other words, the first week of a new year
+** is the week which has the majority of its days in the new year. Week 01
+** might also contain days from the previous year and the week before week
+** 01 of a year is the last week (52 or 53) of the previous year even if
+** it contains days from the new year. A week starts with Monday (day 1)
+** and ends with Sunday (day 7). For example, the first week of the year
+** 1997 lasts from 1996-12-30 to 1997-01-05..."
+** (ado, 1996-01-02)
+*/
+			{
+			int	year;
+			int	base;
+			int	yday;
+			int	wday;
+			int	w;
+
+			year = t->tm_year;
+			base = TM_YEAR_BASE;
+			yday = t->tm_yday;
+			wday = t->tm_wday;
+			for ( ; ; ) {
+				int	len;
+				int	bot;
+				int	top;
+
+				len = isleap_sum(year, base) ?
+					DAYSPERLYEAR :
+					DAYSPERNYEAR;
+				/*
+				** What yday (-3 ... 3) does the ISO year 
+				** begin on?
+				*/
+				bot = ((yday + 11 - wday) % DAYSPERWEEK) - 3;
+				/*
+				** What yday does the NEXT ISO year begin on?
+				*/
+				top = bot - (len % DAYSPERWEEK);
+				if (top < -3)
+					top += DAYSPERWEEK;
+				top += len;
+				if (yday >= top) {
+					++base;
+					w = 1;
+					break;
+				}
+				if (yday >= bot) {
+					w = 1 + ((yday - bot) / DAYSPERWEEK);
+					break;
+				}
+				--base;
+				yday += isleap_sum(year, base) ?
+					DAYSPERLYEAR :
+					DAYSPERNYEAR;
+			}
+			if ((w == 52 && t->tm_mon == TM_JANUARY) ||
+				(w == 1 && t->tm_mon == TM_DECEMBER))
+					w = 53;
+			if (*format == 'V')
+				pt = _conv(w, L"%02d", pt, ptlim);
+			else if (*format == 'g') {
+				*warnp = IN_ALL;
+				pt = _yconv(year, base, 0, 1, pt, ptlim);
+			} else	
+				pt = _yconv(year, base, 1, 1, pt, ptlim);
+			}
+			continue;
+		case 'v':
+			/*
+			** From Arnold Robbins' strftime version 3.0:
+			** "date as dd-bbb-YYYY"
+			** (ado, 1993-05-24)
+			*/
+			pt = _fmt(L"%e-%b-%Y", t, pt, ptlim, warnp);
+			continue;
+		case 'W':
+			pt = _conv((t->tm_yday + DAYSPERWEEK -
+				(t->tm_wday ?
+				(t->tm_wday - 1) :
+				(DAYSPERWEEK - 1))) / DAYSPERWEEK,
+				L"%02d", pt, ptlim);
+			continue;
+		case 'w':
+			pt = _conv(t->tm_wday, L"%d", pt, ptlim);
+			continue;
+		case 'X':
+			pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
+			continue;
+		case 'x':
+			{
+			int	warn2 = IN_SOME;
+
+			pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
+			if (warn2 == IN_ALL)
+				warn2 = IN_THIS;
+			if (warn2 > *warnp)
+				*warnp = warn2;
+			}
+			continue;
+		case 'y':
+			*warnp = IN_ALL;
+			pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, pt, ptlim);
+			continue;
+		case 'Y':
+			pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, pt, ptlim);
+			continue;
+		case 'Z':
+			if (t->tm_zone != NULL)
+				pt = _sadd(t->TM_ZONE, pt, ptlim);
+			else
+				if (t->tm_isdst >= 0)
+					pt = _sadd(tzname[t->tm_isdst != 0], 
+					    pt, ptlim);
+			/*
+			** C99 says that %Z must be replaced by the
+			** empty string if the time zone is not
+			** determinable.
+			*/
+			continue;
+		case 'z':
+			{
+			int		diff;
+			wchar_t const *	sign;
+
+			if (t->tm_isdst < 0)
+				continue;
+			diff = t->tm_gmtoff;
+			if (diff < 0) {
+				sign = L"-";
+				diff = -diff;
+			} else	
+				sign = L"+";
+			pt = _add(sign, pt, ptlim);
+			diff /= SECSPERMIN;
+			diff = (diff / MINSPERHOUR) * 100 +
+				(diff % MINSPERHOUR);
+			pt = _conv(diff, L"%04d", pt, ptlim);
+			}
+			continue;
+		case '+':
+			pt = _fmt(Locale->date_fmt, t, pt, ptlim, warnp);
+			continue;
+		case '%':
+		/*
+		** X311J/88-090 (4.12.3.5): if conversion wchar_t is
+		** undefined, behavior is undefined. Print out the
+		** character itself as printf(3) also does.
+		*/
+		default:
+			if (pt != ptlim)
+				*pt++ = *format;
+			break;
+		}
+	}
+	return pt;
+}
+
+static wchar_t *
+_conv(int n, const wchar_t *format, wchar_t *pt, const wchar_t *ptlim)
+{
+	wchar_t	buf[INT_STRLEN_MAXIMUM(int) + 1];
+
+	(void) swprintf(buf, sizeof buf/sizeof buf[0], format, n);
+	return _add(buf, pt, ptlim);
+}
+
+static wchar_t *
+_add(const wchar_t *str, wchar_t *pt, const wchar_t *ptlim)
+{
+	while (pt < ptlim && (*pt = *str++) != L'\0')
+		++pt;
+	return pt;
+}
+
+static wchar_t *
+_sadd(const char *str, wchar_t *pt, const wchar_t *ptlim)
+{
+	while (pt < ptlim && (*pt = btowc(*str++)) != L'\0')
+		++pt;
+	return pt;
+}
+/*
+** POSIX and the C Standard are unclear or inconsistent about
+** what %C and %y do if the year is negative or exceeds 9999.
+** Use the convention that %C concatenated with %y yields the
+** same output as %Y, and that %Y contains at least 4 bytes,
+** with more only if necessary.
+*/
+
+static wchar_t *
+_yconv(int a, int b, int convert_top, int convert_yy, wchar_t *pt, 
+    const wchar_t *ptlim)
+{
+	register int	lead;
+	register int	trail;
+
+#define DIVISOR	100
+	trail = a % DIVISOR + b % DIVISOR;
+	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
+	trail %= DIVISOR;
+	if (trail < 0 && lead > 0) {
+		trail += DIVISOR;
+		--lead;
+	} else if (lead < 0 && trail > 0) {
+		trail -= DIVISOR;
+		++lead;
+	}
+	if (convert_top) {
+		if (lead == 0 && trail < 0)
+			pt = _add(L"-0", pt, ptlim);
+		else	pt = _conv(lead, L"%02d", pt, ptlim);
+	}
+	if (convert_yy)
+		pt = _conv(((trail < 0) ? -trail : trail), L"%02d", pt, ptlim);
+	return pt;
+}
+