feat: add time offset configuration

kernel/src/Api/Syscall.cpp

@@ -333,6 +333,10 @@ namespace Montauk {
                 return Sys_BtInfo((BtAdapterInfo*)frame->arg1);
             case SYS_SUSPEND:
                 return Sys_Suspend();
+            case SYS_SETTZ:
+                return Sys_SetTZ((int32_t)frame->arg1);
+            case SYS_GETTZ:
+                return Sys_GetTZ();
             default:
                 return -1;
         }

kernel/src/Api/Syscall.hpp

@@ -174,6 +174,10 @@ namespace Montauk {
     /* Power.hpp */
     static constexpr uint64_t SYS_SUSPEND      = 89;
 
+    /* Time.hpp */
+    static constexpr uint64_t SYS_SETTZ         = 90;
+    static constexpr uint64_t SYS_GETTZ         = 91;
+
     static constexpr int SOCK_TCP = 1;
     static constexpr int SOCK_UDP = 2;
 

kernel/src/Api/Time.hpp

@@ -29,4 +29,13 @@ namespace Montauk {
         out->Minute = dt.Minute;
         out->Second = dt.Second;
     }
+
+    static int64_t Sys_SetTZ(int32_t offsetMinutes) {
+        Timekeeping::SetTZOffset(offsetMinutes);
+        return 0;
+    }
+
+    static int64_t Sys_GetTZ() {
+        return (int64_t)Timekeeping::GetTZOffset();
+    }
 };

kernel/src/Timekeeping/Time.cpp

@@ -11,6 +11,7 @@
 using namespace Kt;
 
 static int64_t g_bootEpoch = 0;
+static int g_tzOffsetMinutes = 60; /* Default: UTC+1 (CET) until userspace overrides */
 
 static bool IsLeapYear(int year) {
     return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
@@ -68,34 +69,29 @@ static Timekeeping::DateTime EpochToDate(int64_t epoch) {
 
 void Timekeeping::Init(uint16_t Year, uint8_t Month, uint8_t Day, uint8_t Hour, uint8_t Minute, uint8_t Second) {
     g_bootEpoch = DateToEpoch(Year, Month, Day, Hour, Minute, Second);
-    /* Hardcode CET for now */
-    TimeZone CET = {
-        "Central European Time",
-        "CET",
-        1, /* UTC+1 */
-        0,
-        false
-    };
 
-    Kt::KernelLogStream(INFO, "Timekeeping Service") << "Setting time zone to " << CET.TZLongName << " (" << CET.TZShortName << ")";
+    /* Apply default timezone offset for boot log display */
+    int adjMin = Minute + (g_tzOffsetMinutes % 60);
+    int adjHour = Hour + (g_tzOffsetMinutes / 60);
+    if (adjMin < 0) { adjMin += 60; adjHour -= 1; }
+    if (adjMin >= 60) { adjMin -= 60; adjHour += 1; }
+    if (adjHour < 0) adjHour += 24;
+    if (adjHour >= 24) adjHour -= 24;
 
-    Minute = Minute + CET.MinuteOffset;
-    Hour = Hour + CET.HourOffset;
-    if (Minute >= 60) {
-        Minute -= 60;
-        Hour += 1;
-    }
-    if (Hour >= 24) {
-        Hour -= 24;
-        Day += 1;
-        /* Note: No month/day overflow handling yet */
-    }
+    int offH = g_tzOffsetMinutes / 60;
+    int offM = g_tzOffsetMinutes % 60;
+    if (offM < 0) offM = -offM;
+
+    Kt::KernelLogStream(INFO, "Timekeeping Service") << "Time zone: UTC"
+        << (offH >= 0 ? "+" : "") << offH
+        << (offM ? ":" : "") << (offM >= 10 ? "" : (offM ? "0" : ""))
+        << (offM ? offM : 0);
 
     kcp::cstringstream minuteStream;
-    if (Minute < 10) {
+    if (adjMin < 10) {
         minuteStream << "0";
     }
-    minuteStream << Minute;
+    minuteStream << adjMin;
     CString minuteStr = minuteStream.c_str();
 
     kcp::cstringstream secondStream;
@@ -111,12 +107,10 @@ void Timekeeping::Init(uint16_t Year, uint8_t Month, uint8_t Day, uint8_t Hour,
         << Day << " "
         << Months[Month] << " "
         << Year << ", "
-        << Hour << ":"
-
+        << adjHour << ":"
         << minuteStr << ":"
         << secondStr
-        << " (" << CET.TZLongName << ")";
-
+        << " (UTC" << (offH >= 0 ? "+" : "") << offH << ")";
 
     CString dateString = panelStr.c_str();
 
@@ -128,5 +122,13 @@ int64_t Timekeeping::GetUnixTimestamp() {
 }
 
 Timekeeping::DateTime Timekeeping::GetDateTime() {
-    return EpochToDate(GetUnixTimestamp());
+    return EpochToDate(GetUnixTimestamp() + (int64_t)g_tzOffsetMinutes * 60);
+}
+
+void Timekeeping::SetTZOffset(int totalMinutes) {
+    g_tzOffsetMinutes = totalMinutes;
+}
+
+int Timekeeping::GetTZOffset() {
+    return g_tzOffsetMinutes;
 }

kernel/src/Timekeeping/Time.hpp

@@ -53,4 +53,7 @@ namespace Timekeeping {
     void Init(uint16_t Year, uint8_t Month, uint8_t Day, uint8_t Hour, uint8_t Minute, uint8_t Second);
     int64_t GetUnixTimestamp();
     DateTime GetDateTime();
+
+    void SetTZOffset(int totalMinutes);
+    int GetTZOffset();
 };