Convert Linux internal time format to Windows 1601 epoch.

base/time_unittest.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <time.h>
 
 #include "base/platform_thread.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 122 matching lines @@
               TimeDelta::FromMicroseconds(2000));
   EXPECT_EQ(13, TimeDelta::FromDays(13).InDays());
   EXPECT_EQ(13, TimeDelta::FromHours(13).InHours());
   EXPECT_EQ(13, TimeDelta::FromMinutes(13).InMinutes());
   EXPECT_EQ(13, TimeDelta::FromSeconds(13).InSeconds());
   EXPECT_EQ(13.0, TimeDelta::FromSeconds(13).InSecondsF());
   EXPECT_EQ(13, TimeDelta::FromMilliseconds(13).InMilliseconds());
   EXPECT_EQ(13.0, TimeDelta::FromMilliseconds(13).InMillisecondsF());
   EXPECT_EQ(13, TimeDelta::FromMicroseconds(13).InMicroseconds());
 }
+
+#if defined(OS_LINUX) || defined(OS_WINDOWS)  // TODO(deanm): Mac.
+// Our internal time format is serialized in things like databases, so it's
+// important that it's consistent across all our platforms.  We use the 1601
+// Windows epoch as the internal format across all platforms.
+TEST(TimeDelta, WindowsEpoch) {
+  Time::Exploded exploded;
+  exploded.year = 1970;
+  exploded.month = 1;
+  exploded.day_of_week = 0;  // Should be unusued.
+  exploded.day_of_month = 1;
+  exploded.hour = 0;
+  exploded.minute = 0;
+  exploded.second = 0;
+  exploded.millisecond = 0;
+  Time t = Time::FromUTCExploded(exploded);
+  // Unix 1970 epoch.
+  EXPECT_EQ(GG_INT64_C(11644473600000000), t.ToInternalValue());
+
+  // We can't test 1601 epoch, since the system time functions on Linux
+  // only compute years starting from 1900.
+}
+#endif