Implement time conversion routines for Unix and XT epoch formats

xtoskrnl/rtl/data.cc

@@ -11,3 +11,15 @@
 
 /* This is required for floating numbers to keep LLVM happy */
 XTCLINK INT _fltused = 0xFEEDBULL;
+
+/* Lookup table for days in a month, Index 0 is normal year, Index 1 is leap year */
+CUSHORT RTL::Time::DaysInMonth[2][12] = {
+    {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
+    {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
+};
+
+/* Lookup table for days preceding a month, Index 0 is normal year, Index 1 is leap year */
+CUSHORT RTL::Time::DaysPrecedingMonth[2][12] = {
+    {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
+    {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
+};