time: Use custom RTC settings if applicable for game

src/core/hle/service/time/time.cpp

@@ -12,9 +12,17 @@
 #include "core/hle/kernel/client_session.h"
 #include "core/hle/service/time/interface.h"
 #include "core/hle/service/time/time.h"
+#include "core/settings.h"
 
 namespace Service::Time {
 
+static s64 GetSecondsSinceEpoch() {
+    return std::chrono::duration_cast<std::chrono::seconds>(
+               std::chrono::system_clock::now().time_since_epoch())
+               .count() +
+           Settings::values.custom_rtc_differential;
+}
+
 static void PosixToCalendar(u64 posix_time, CalendarTime& calendar_time,
                             CalendarAdditionalInfo& additional_info,
                             [[maybe_unused]] const TimeZoneRule& /*rule*/) {
@@ -68,9 +76,7 @@ public:
 
 private:
     void GetCurrentTime(Kernel::HLERequestContext& ctx) {
-        const s64 time_since_epoch{std::chrono::duration_cast<std::chrono::seconds>(
-                                       std::chrono::system_clock::now().time_since_epoch())
-                                       .count()};
+        const s64 time_since_epoch{GetSecondsSinceEpoch()};
         LOG_DEBUG(Service_Time, "called");
 
         IPC::ResponseBuilder rb{ctx, 4};
@@ -266,9 +272,7 @@ void Module::Interface::GetClockSnapshot(Kernel::HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
     const auto initial_type = rp.PopRaw<u8>();
 
-    const s64 time_since_epoch{std::chrono::duration_cast<std::chrono::seconds>(
-                                   std::chrono::system_clock::now().time_since_epoch())
-                                   .count()};
+    const s64 time_since_epoch{GetSecondsSinceEpoch()};
 
     const std::time_t time(time_since_epoch);
     const std::tm* tm = std::localtime(&time);

src/yuzu_cmd/default_ini.h

@@ -186,8 +186,8 @@ rng_seed =
 # Sets the current time (in seconds since 12:00 AM Jan 1, 1970) that will be used by the time service
 # This will auto-increment, with the time set being the time the game is started
 # This override will only occur if custom_rtc_enabled is true, otherwise the current time is used
-custom_rtc_enabled = 
-custom_rtc = 
+custom_rtc_enabled =
+custom_rtc =
 
 # Sets the account username, max length is 32 characters
 # yuzu (default)