mpd/src/time/Zone.cxx
2023-03-06 14:59:48 +01:00

39 lines
772 B
C++

// SPDX-License-Identifier: BSD-2-Clause
// Copyright CM4all GmbH
// author: Max Kellermann <mk@cm4all.com>
#include "Zone.hxx"
#ifdef _WIN32
#include <profileapi.h>
#include <sysinfoapi.h>
#include <timezoneapi.h>
#else
#include <time.h>
#endif
int
GetTimeZoneOffset() noexcept
{
#ifdef _WIN32
TIME_ZONE_INFORMATION TimeZoneInformation;
DWORD tzi = GetTimeZoneInformation(&TimeZoneInformation);
int offset = -TimeZoneInformation.Bias * 60;
if (tzi == TIME_ZONE_ID_STANDARD)
offset -= TimeZoneInformation.StandardBias * 60;
if (tzi == TIME_ZONE_ID_DAYLIGHT)
offset -= TimeZoneInformation.DaylightBias * 60;
return offset;
#else
time_t t = 1234567890;
struct tm tm;
tm.tm_isdst = 0;
struct tm *p = &tm;
gmtime_r(&t, p);
return t - mktime(p);
#endif
}