Index volume scan by time, change internal data structure from unordered to ordered map

wxdata/source/scwx/util/time.cpp

@@ -0,0 +1,20 @@
+#include <scwx/util/time.hpp>
+
+namespace scwx
+{
+namespace util
+{
+
+std::chrono::system_clock::time_point
+TimePoint(uint16_t modifiedJulianDate, uint32_t milliseconds)
+{
+   using namespace std::chrono;
+   using sys_days       = time_point<system_clock, days>;
+   constexpr auto epoch = sys_days {1969y / December / 31d};
+
+   return epoch + (modifiedJulianDate * 24h) +
+          std::chrono::milliseconds {milliseconds};
+}
+
+} // namespace qt
+} // namespace scwx