Index: libcxx/src/filesystem/filesystem_common.h
===================================================================
--- libcxx/src/filesystem/filesystem_common.h
+++ libcxx/src/filesystem/filesystem_common.h
@@ -522,7 +522,11 @@
   }
 };
 
+#if defined(_LIBCPP_WIN32API)
+using fs_time = time_util<file_time_type, int64_t, TimeSpec>;
+#else
 using fs_time = time_util<file_time_type, time_t, TimeSpec>;
+#endif
 
 #if defined(__APPLE__)
 TimeSpec extract_mtime(StatT const& st) { return st.st_mtimespec; }
@@ -532,6 +536,7 @@
 TimeSpec extract_atime(StatT const& st) { return st.st_atim; }
 #endif
 
+#if !defined(_LIBCPP_WIN32API)
 // allow the utimes implementation to compile even it we're not going
 // to use it.
 
@@ -571,6 +576,7 @@
   return posix_utimensat(p, TS, ec);
 #endif
 }
+#endif /* !_LIBCPP_WIN32API */
 
 } // namespace
 } // end namespace detail
Index: libcxx/src/filesystem/operations.cpp
===================================================================
--- libcxx/src/filesystem/operations.cpp
+++ libcxx/src/filesystem/operations.cpp
@@ -39,7 +39,7 @@
 # define _LIBCPP_FILESYSTEM_USE_FSTREAM
 #endif
 
-#if !defined(CLOCK_REALTIME)
+#if !defined(CLOCK_REALTIME) && !defined(_LIBCPP_WIN32API)
 # include <sys/time.h> // for gettimeofday and timeval
 #endif
 
@@ -334,6 +334,23 @@
   return ret;
 }
 
+TimeSpec filetime_to_timespec(FILETIME ft) {
+  LARGE_INTEGER li;
+  li.LowPart = ft.dwLowDateTime;
+  li.HighPart = ft.dwHighDateTime;
+  return filetime_to_timespec(li);
+}
+
+FILETIME timespec_to_filetime(TimeSpec ts) {
+  LARGE_INTEGER li;
+  li.QuadPart =
+      ts.tv_nsec / 100 + (ts.tv_sec + FILE_TIME_OFFSET_SECS) * 10000000;
+  FILETIME ft;
+  ft.dwLowDateTime = li.LowPart;
+  ft.dwHighDateTime = li.HighPart;
+  return ft;
+}
+
 int set_errno() {
   errno = static_cast<int>(win_err_to_errc(GetLastError()));
   return -1;
@@ -593,7 +610,14 @@
 
 _FilesystemClock::time_point _FilesystemClock::now() noexcept {
   typedef chrono::duration<rep> __secs;
-#if defined(CLOCK_REALTIME)
+#if defined(_LIBCPP_WIN32API)
+  typedef chrono::duration<rep, nano> __nsecs;
+  FILETIME time;
+  GetSystemTimeAsFileTime(&time);
+  TimeSpec tp = detail::filetime_to_timespec(time);
+  return time_point(__secs(tp.tv_sec) +
+                    chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
+#elif defined(CLOCK_REALTIME)
   typedef chrono::duration<rep, nano> __nsecs;
   struct timespec tp;
   if (0 != clock_gettime(CLOCK_REALTIME, &tp))
@@ -1125,6 +1149,18 @@
   using detail::fs_time;
   ErrorHandler<void> err("last_write_time", ec, &p);
 
+#if defined(_LIBCPP_WIN32API)
+  TimeSpec ts;
+  if (!fs_time::convert_to_timespec(ts, new_time) ||
+      new_time == file_time_type::min())
+    return err.report(errc::value_too_large);
+  detail::WinHandle h(p.c_str(), FILE_WRITE_ATTRIBUTES, 0);
+  if (!h)
+    return err.report(detail::capture_last_error());
+  FILETIME last_write = timespec_to_filetime(ts);
+  if (!SetFileTime(h, nullptr, nullptr, &last_write))
+    return err.report(detail::capture_last_error());
+#else
   error_code m_ec;
   array<TimeSpec, 2> tbuf;
 #if !defined(_LIBCPP_USE_UTIMENSAT)
@@ -1146,6 +1182,7 @@
   detail::set_file_times(p, tbuf, m_ec);
   if (m_ec)
     return err.report(m_ec);
+#endif
 }
 
 void __permissions(const path& p, perms prms, perm_options opts,