[*] I'm going to be autistic and say "everybody" is (read: industry midwits are) wrong about dates

(amend comments)

Include/Aurora/Time/TM.hpp

@@ -11,42 +11,88 @@ namespace Aurora::Time
 { 
     struct tm
     {
-        int tm_sec {};
+        int year {};                 // The absolute gregorian-calendar year
-        int tm_min {};
+        int mon {};                  // Months since January
-        int tm_hour {};
+
-        int tm_mday {1};
+        int mday {};                 // Days since last month
-        int tm_mon {};
+        AuOptional<int> wday {};     // Days since Monday   [usually ignored]
-        int tm_year {70};
+        AuOptional<int> yday {};     // Days since January  [usually ignored]
-        int tm_wday {};
+
-        int tm_yday {};
+        int hour {};                 // Hours since yesterday
-        int tm_isdst {-1};
+        int min {};                  // Minutes since the hour
+        int sec {};                  // Seconds since the minute
+        AuOptionalEx<bool> isdst {};
 
         template<typename Dest_t>
         void CopyTo(Dest_t &out) const
         {
-            out.tm_sec = tm_sec;
+            out.tm_sec  = sec;
-            out.tm_min = tm_min;
+            out.tm_min  = min;
-            out.tm_hour = tm_hour;
+            out.tm_hour = hour;
-            out.tm_mday = tm_mday;
+            out.tm_mday = mday + 1;
-            out.tm_mon = tm_mon;
+            out.tm_mon  = mon;
-            out.tm_year = tm_year;
+
-            out.tm_wday = tm_wday;
+        #if 0
-            out.tm_yday = tm_yday;
+            if (year < 1900)
-            out.tm_isdst = tm_isdst;
+            {
+                out.tm_year = 0;
+            }
+            else
+        #endif
+            {
+                out.tm_year = year - 1900;
+            }
+            
+            if (wday == 6)
+            {
+                out.tm_wday = 0;
+            }
+            else
+            {
+                out.tm_wday = wday.value() + 1;
+            }
+
+            out.tm_yday = yday.value();
+
+            if (!isdst.HasValue())
+            {
+                out.tm_isdst = -1;
+            }
+            else
+            {
+                out.tm_isdst = isdst.value();
+            }
         }
 
         template<typename In_t>
         void CopyFrom(const In_t &in)
         {
-            tm_sec = in.tm_sec;
+            sec = in.tm_sec;
-            tm_min = in.tm_min;
+            min = in.tm_min;
-            tm_hour = in.tm_hour;
+            hour = in.tm_hour;
-            tm_mday = in.tm_mday;
+            mday = in.tm_mday - 1;
-            tm_mon = in.tm_mon;
+            mon = in.tm_mon;
-            tm_year = in.tm_year;
+            year = in.tm_year + 1900;
-            tm_wday = in.tm_wday;
+
-            tm_yday = in.tm_yday;
+            if (in.tm_wday == 0)
-            tm_isdst = in.tm_isdst;
+            {
+                wday = 6;
+            }
+            else
+            {
+                wday = in.tm_wday - 1;
+            }
+
+            yday = in.tm_yday;
+            isdst = in.tm_isdst; // (dont normalize -1. it's a quirk of most modern CRTs we can exploit to easily solve the [user-input + how do i guess DST] issue)
+                                 // (stupid c programs shouldn't be exploiting this anyway. assume all std::tm, ::tm, and similar types calling into us follow boolean logic)
         }
+
+        // Note (*): We don't give a single solitary fuck about what ISO 8601 says nor the intentions of braindead boomers who thought there were 61 seconds to an hour...
+        //           Sunday is not a Weekday; it's apart of the Week-END. No English speaker will disagree with this once we get past the obvious gaslighting attempts from NGOs and indoctrination institutions.
+        //           In my estimation, it's every English speeker ever born after the Stuarts (17xxs+) versus a handful of CIA boys and the International Organization for Standardization
+        //           In my tradition of upholding da norf, we're sticking by the 19th century industrialized understanding of time.
+        // tm_wday is the day offset since Monday, not days since last week.
+        // tm_mday is the day offset since the beginning of the month, not the calendar number - that's to say we deviate from other impls by asserting these members are all offsets, not whatever some CIA fuckbuddies at ANSI said it is.
     };
 }

Source/Time/AuCivilTime.cpp

@@ -169,7 +169,7 @@ namespace Aurora::Time
 
     AUKN_SYM tm NormalizeCivilTimezone(const Time::tm &time, ETimezoneShift shift)
     {
-        if ((time.tm_isdst == 0) && (shift == ETimezoneShift::eUTC))
+        if ((time.isdst.ValueOr(-1) == 0) && (shift == ETimezoneShift::eUTC))
         {
             return time;
         }