Use std::chrono instead of std::vector<int> to store start date

opm/io/eclipse/ESmry.hpp

@@ -19,6 +19,7 @@
 #ifndef OPM_IO_ESMRY_HPP
 #define OPM_IO_ESMRY_HPP
 
+#include <chrono>
 #include <ostream>
 #include <string>
 #include <unordered_map>
@@ -46,7 +47,7 @@ public:
     std::vector<float> get_at_rstep(const std::string& name) const;
     std::vector<float> get_at_rstep(const SummaryNode& node) const;
 
-    const std::vector<int>& get_startdat() const { return startdat; }
+    std::chrono::system_clock::time_point startdate() const { return startdat; }
 
     const std::vector<std::string>& keywordList() const;
     const std::vector<SummaryNode>& summaryNodeList() const;
@@ -72,7 +73,7 @@ private:
     std::unordered_map<std::string, std::string> kwunits;
 
     std::vector<int> seqIndex;
-    std::vector<int> startdat;
+    std::chrono::system_clock::time_point startdat;
 
     std::vector<std::string> checkForMultipleResultFiles(const Opm::filesystem::path& rootN, bool formatted) const;
 

python/cxx/eclipse_io.cpp

@@ -1,6 +1,7 @@
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
 #include <pybind11/numpy.h>
+#include <pybind11/chrono.h>
 
 #include <opm/io/eclipse/EclFile.hpp>
 #include <opm/io/eclipse/EclIOdata.hpp>
@@ -9,6 +10,7 @@
 #include <opm/io/eclipse/EGrid.hpp>
 #include <opm/io/eclipse/ERft.hpp>
 #include <opm/io/eclipse/EclOutput.hpp>
+#include <opm/common/utility/TimeService.hpp>
 
 #include <opm/common/utility/numeric/calculateCellVol.hpp>
 
@@ -272,6 +274,27 @@ npArray get_rft_vector_Index(Opm::EclIO::ERft * file_ptr,const std::string& name
 }
 
 
+
+/*
+  This insane time based trickery is to address the following situation:
+
+  1. OPM uses UTC times internally - so the ESmry::startdate() method will
+     return a timepoint which should be interpreted in UTC.
+
+  2. The pybind11 std::chrono <-> datetime mapping uses localtime. We therefor
+     convert the timepoint returned from UTC to localtime before proceeding to
+     the pybind11 conversion.
+*/
+
+std::chrono::system_clock::time_point esmry_start_date(const Opm::EclIO::ESmry * esmry) {
+    auto utc_chrono   = esmry->startdate();
+    auto utc_time_t   = std::chrono::system_clock::to_time_t( utc_chrono );
+    auto utc_ts       = Opm::TimeStampUTC( utc_time_t );
+    auto local_time_t = Opm::asLocalTimeT( utc_ts );
+    return std::chrono::system_clock::from_time_t( local_time_t );
+}
+
+
 }
 
 
@@ -317,7 +340,7 @@ void python::common::export_IO(py::module& m) {
         .def("__len__", &Opm::EclIO::ESmry::numberOfTimeSteps)
         .def("__get_all", &get_smry_vector)
         .def("__get_at_rstep", &get_smry_vector_at_rsteps)
-        .def("__get_startdat", &Opm::EclIO::ESmry::get_startdat)
+        .def_property_readonly("start_date", &esmry_start_date)
         .def_property_readonly("list_of_keys", &Opm::EclIO::ESmry::keywordList);
 
    py::class_<Opm::EclIO::EGrid>(m, "EGrid")

python/python/opm/io/ecl/__init__.py

@@ -85,22 +85,6 @@ def contains_erst(self, arg):
         raise ValueError("expecting tuple (array name , report step number) or \
                           or report step number")
 
-@property
-def esmry_start_date(self):
-
-    startd = self.__get_startdat()
-
-    if len(startd) < 6:
-        for n in range(len(startd), 6):
-            startd.append(0)
-
-
-    sec = startd[5] // 1000000
-    microseconds = startd[5] % 1000000
-
-    return datetime.datetime( startd[2], startd[1], startd[0], startd[3],
-                              startd[4], sec, microseconds )
-
 @property
 def esmry_end_date(self):
 
@@ -226,7 +210,6 @@ setattr(ERst, "__contains__", contains_erst)
 setattr(ERst, "arrays", erst_get_list_of_arrays)
 setattr(ERst, "__getitem__", getitem_erst)
 
-setattr(ESmry, "start_date", esmry_start_date)
 setattr(ESmry, "end_date", esmry_end_date)
 setattr(ESmry, "__getitem__", getitem_esmry)
 

src/opm/io/eclipse/ESmry.cpp

@@ -19,6 +19,7 @@
 #include <opm/io/eclipse/ESmry.hpp>
 
 #include <algorithm>
+#include <chrono>
 #include <exception>
 #include <iterator>
 #include <limits>
@@ -27,7 +28,7 @@
 #include <string>
 
 #include <opm/common/utility/FileSystem.hpp>
-
+#include <opm/common/utility/TimeService.hpp>
 #include <opm/io/eclipse/EclFile.hpp>
 /*
 
@@ -47,7 +48,36 @@
      RXF            +-+-+-         32768*R1(R2 + 10) |       11        RXF:2-3
      SOFX           OP_1           12675             |       12        SOFX:OP_1:12675, SOFX:OP_1:i,j,jk
 
- */
+*/
+
+
+namespace {
+
+std::chrono::system_clock::time_point make_date(const std::vector<int>& datetime) {
+    auto day = datetime[0];
+    auto month = datetime[1];
+    auto year = datetime[2];
+    auto hour = 0;
+    auto minute = 0;
+    auto second = 0;
+    auto usec = 0;
+
+    if (datetime.size() == 6) {
+        hour = datetime[3];
+        minute = datetime[4];
+        auto total_usec = datetime[5];
+        second = total_usec / 1000000;
+        usec = total_usec - second * 1000000;
+    }
+
+
+    const auto ts = Opm::TimeStampUTC{ Opm::TimeStampUTC::YMD{ year, month, day}}.hour(hour).minutes(minute).seconds(second);
+    return std::chrono::system_clock::from_time_t( Opm::asTimeT(ts) );
+}
+
+
+}
+
 
 namespace Opm { namespace EclIO {
 
@@ -109,7 +139,7 @@ ESmry::ESmry(const std::string &filename, bool loadBaseRunData) :
         const std::vector<int> nums = smspec.get<int>("NUMS");
         const std::vector<std::string> units = smspec.get<std::string>("UNITS");
 
-        startdat = smspec.get<int>("STARTDAT");
+        this->startdat = make_date(smspec.get<int>("STARTDAT"));
 
         for (unsigned int i=0; i<keywords.size(); i++) {
             const std::string keyString = makeKeyString(keywords[i], wgnames[i], nums[i]);
@@ -160,7 +190,7 @@ ESmry::ESmry(const std::string &filename, bool loadBaseRunData) :
         const std::vector<int> nums = smspec_rst.get<int>("NUMS");
         const std::vector<std::string> units = smspec_rst.get<std::string>("UNITS");
 
-        startdat = smspec_rst.get<int>("STARTDAT");
+        this->startdat = make_date(smspec_rst.get<int>("STARTDAT"));
 
         for (size_t i = 0; i < keywords.size(); i++) {
             const std::string keyString = makeKeyString(keywords[i], wgnames[i], nums[i]);