diff --git a/tests/bugs/gh_5959_test.py b/tests/bugs/gh_5959_test.py
new file mode 100644
index 00000000..65bda98e
--- /dev/null
+++ b/tests/bugs/gh_5959_test.py
@@ -0,0 +1,103 @@
+#coding:utf-8
+
+"""
+ID:          issue-5959
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/5959
+TITLE:       Add support for QUARTER to EXTRACT, FIRST_DAY and LAST_DAY [CORE5693]
+NOTES:
+    [12.05.2023] pzotov
+    Checked on 5.0.0.1046
+"""
+
+import pytest
+from firebird.qa import *
+
+db = db_factory()
+
+test_script = """
+    set list on;
+
+    select
+        dts
+        ,extract(quarter from dts ) as extract_quarter
+        ,first_day(of quarter from dts) as first_day_of_quarter
+        ,last_day(of quarter from dts) as last_day_of_quarter
+    from (
+        select date '01.01.0001' as dts from rdb$database
+    );
+
+
+    select
+        dts
+        ,extract(quarter from dts ) as extract_quarter
+        ,first_day(of quarter from dts) as first_day_of_quarter
+        ,last_day(of quarter from dts) as last_day_of_quarter
+    from (
+        select timestamp '29.02.2020 19:20:21.223' as dts from rdb$database
+    );
+
+    select
+        dts
+        ,extract(quarter from dts ) as extract_quarter
+        ,first_day(of quarter from dts) as first_day_of_quarter
+        ,last_day(of quarter from dts) as last_day_of_quarter
+    from (
+        select cast(null as timestamp) as dts from rdb$database
+    );
+
+    select
+        dts
+        ,extract(quarter from dts ) as extract_quarter
+        ,first_day(of quarter from dts) as first_day_of_quarter
+        ,last_day(of quarter from dts) as last_day_of_quarter
+    from (
+        select cast( '2018-01-02 04:04:04.4444 +14:0' as timestamp with time zone) as dts from rdb$database
+    );
+
+    select
+        dts
+        ,extract(quarter from dts ) as extract_quarter
+        ,first_day(of quarter from dts) as first_day_of_quarter
+        ,last_day(of quarter from dts) as last_day_of_quarter
+    from (
+        select cast( '2019-03-23 11:31:05.0001 america/new_york' as timestamp with time zone) as dts from rdb$database
+    );
+
+"""
+
+act = isql_act('db', test_script)
+
+# NB, doc/sql.extensions/README.builtin_functions.txt:
+# "When a timestamp is passed the return value __preserves__ the time part" 
+expected_stdout = """
+    DTS                             0001-01-01
+    EXTRACT_QUARTER                 1
+    FIRST_DAY_OF_QUARTER            0001-01-01
+    LAST_DAY_OF_QUARTER             0001-03-31
+
+    DTS                             2020-02-29 19:20:21.2230
+    EXTRACT_QUARTER                 1
+    FIRST_DAY_OF_QUARTER            2020-01-01 19:20:21.2230
+    LAST_DAY_OF_QUARTER             2020-03-31 19:20:21.2230
+
+    DTS                             <null>
+    EXTRACT_QUARTER                 <null>
+    FIRST_DAY_OF_QUARTER            <null>
+    LAST_DAY_OF_QUARTER             <null>
+
+    DTS                             2018-01-02 04:04:04.4444 +14:00
+    EXTRACT_QUARTER                 1
+    FIRST_DAY_OF_QUARTER            2018-01-01 04:04:04.4444 +14:00
+    LAST_DAY_OF_QUARTER             2018-03-31 04:04:04.4444 +14:00
+
+    DTS                             2019-03-23 11:31:05.0001 America/New_York
+    EXTRACT_QUARTER                 1
+    FIRST_DAY_OF_QUARTER            2019-01-01 11:31:05.0001 America/New_York
+    LAST_DAY_OF_QUARTER             2019-03-31 11:31:05.0001 America/New_York
+"""
+
+@pytest.mark.version('>=5.0')
+def test_1(act: Action):
+    act.expected_stdout = expected_stdout
+    act.execute()
+    assert act.clean_stdout == act.clean_expected_stdout