Add option to set Monday as first day of week

QueryEngine/Execute.cpp

@@ -125,6 +125,7 @@ bool g_enable_smem_non_grouped_agg{
             // non-grouped aggregates
 bool g_is_test_env{false};  // operating under a unit test environment. Currently only
                             // limits the allocation for the output buffer arena
+bool g_monday_first_weekday{false};
 
 size_t g_approx_quantile_buffer{1000};
 size_t g_approx_quantile_centroids{300};

QueryEngine/ExtractFromTime.cpp

@@ -72,7 +72,7 @@ extern "C" ALWAYS_INLINE DEVICE int64_t extract_nanosecond(const int64_t lcltime
 // First day of epoch is Thursday, so + 4 to have Sunday=0.
 extern "C" ALWAYS_INLINE DEVICE int64_t extract_dow(const int64_t lcltime) {
   int64_t const days_past_epoch = floor_div(lcltime, kSecsPerDay);
-  return unsigned_mod(days_past_epoch + 4, kDaysPerWeek);
+  return unsigned_mod(days_past_epoch + 4 - g_monday_first_weekday, kDaysPerWeek);
 }
 
 extern "C" ALWAYS_INLINE DEVICE int64_t extract_quarterday(const int64_t lcltime) {

Tests/ExecuteTest.cpp

@@ -4903,6 +4903,31 @@ TEST(Select, Time) {
                                   "test WHERE (m >= TIMESTAMP(3) '1970-01-01 "
                                   "00:00:00.000') GROUP BY key0 ORDER BY key0 LIMIT 1;",
                                   dt)));
+
+    // test first weekday option
+    bool prev_monday_first_weekday = g_monday_first_weekday;
+    g_monday_first_weekday = true;
+    // Monday
+    ASSERT_EQ(0,
+              v<int64_t>(run_simple_agg("SELECT EXTRACT(DOW FROM CAST('2008-03-03 "
+                                        "20:00:11' AS TIMESTAMP)) FROM test limit 1;",
+                                        dt)));
+    // Wednesday
+    ASSERT_EQ(2,
+              v<int64_t>(run_simple_agg("SELECT EXTRACT(DOW FROM CAST('2021-01-27 "
+                                        "20:15:12' AS TIMESTAMP)) FROM test limit 1;",
+                                        dt)));
+    // Saturday
+    ASSERT_EQ(5,
+              v<int64_t>(run_simple_agg("SELECT EXTRACT(DOW FROM CAST('2020-11-14 "
+                                        "14:47:12' AS TIMESTAMP)) FROM test limit 1;",
+                                        dt)));
+    // Sunday
+    ASSERT_EQ(6,
+              v<int64_t>(run_simple_agg("SELECT EXTRACT(DOW FROM CAST('2020-09-27 "
+                                        "21:30:12' AS TIMESTAMP)) FROM test limit 1;",
+                                        dt)));
+    g_monday_first_weekday = prev_monday_first_weekday;
   }
 }
 

ThriftHandler/CommandLineOptions.cpp

@@ -265,6 +265,11 @@ void CommandLineOptions::fillOptions() {
           ->default_value(g_null_div_by_zero)
           ->implicit_value(true),
       "Return null on division by zero instead of throwing an exception.");
+  help_desc.add_options()("monday-first-weekday",
+                          po::value<bool>(&g_monday_first_weekday)
+                              ->default_value(g_monday_first_weekday)
+                              ->implicit_value(true),
+                          "Set Monday as first day of week instead of Sunday");
   help_desc.add_options()(
       "num-reader-threads",
       po::value<size_t>(&num_reader_threads)->default_value(num_reader_threads),

ThriftHandler/CommandLineOptions.h

@@ -179,6 +179,7 @@ extern size_t g_gpu_smem_threshold;
 extern bool g_enable_smem_non_grouped_agg;
 extern bool g_enable_smem_grouped_non_count_agg;
 extern bool g_use_estimator_result_cache;
+extern bool g_monday_first_weekday;
 
 extern int64_t g_omni_kafka_seek;
 extern size_t g_leaf_count;