diff --git a/lib/dl_formula_ref/dl_formula_ref/categories/type_conversion.py b/lib/dl_formula_ref/dl_formula_ref/categories/type_conversion.py
index aa3cf6221..f3898f0f6 100644
--- a/lib/dl_formula_ref/dl_formula_ref/categories/type_conversion.py
+++ b/lib/dl_formula_ref/dl_formula_ref/categories/type_conversion.py
@@ -22,11 +22,11 @@
             "ch_toStartOfInterval": AliasedLinkResource(
                 url=_("https://clickhouse.com/docs/en/sql-reference/functions/date-time-functions#tostartofinterval")
             ),
-            "geopolygon_link": AliasedLinkResource(url=_("../concepts/data-types.md#geopolygon")),
+            "geopolygon_link": AliasedLinkResource(url=_("../dataset/data-types.md#geopolygon")),
             "timezone_link": AliasedLinkResource(
                 url=_("https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List")
             ),
-            "tree_link": AliasedLinkResource(url=_("../concepts/data-types.md#tree-hierarchy")),
+            "tree_link": AliasedLinkResource(url=_("../dataset/data-types.md#tree-hierarchy")),
             "unix_ts": AliasedLinkResource(url=_("https://en.wikipedia.org/wiki/Unix_time")),
         }
     ),
diff --git a/lib/dl_formula_ref/dl_formula_ref/example_data.json b/lib/dl_formula_ref/dl_formula_ref/example_data.json
index f13a61c8c..62d1938b0 100644
--- a/lib/dl_formula_ref/dl_formula_ref/example_data.json
+++ b/lib/dl_formula_ref/dl_formula_ref/example_data.json
@@ -98,13 +98,16 @@
         {
             "columns": [
                 {
-                    "name": "Warmest Month",
-                    "type": "STRING"
+                    "name": "Warmest Day",
+                    "type": "DATE"
                 }
             ],
             "rows": [
                 [
-                    "July"
+                    {
+                        "__type__": "date",
+                        "__value__": "2019-03-01"
+                    }
                 ]
             ]
         }
@@ -114,13 +117,16 @@
         {
             "columns": [
                 {
-                    "name": "Coldest Month",
-                    "type": "STRING"
+                    "name": "Coldest Day",
+                    "type": "DATE"
                 }
             ],
             "rows": [
                 [
-                    "January"
+                    {
+                        "__type__": "date",
+                        "__value__": "2019-03-08"
+                    }
                 ]
             ]
         }
@@ -3568,6 +3574,59 @@
             ]
         }
     ],
+    [
+        "MONTH.Example with custom first day of the week",
+        {
+            "columns": [
+                {
+                    "name": "Date",
+                    "type": "DATE"
+                },
+                {
+                    "name": "Month",
+                    "type": "INTEGER"
+                },
+                {
+                    "name": "Month name",
+                    "type": "STRING"
+                }
+            ],
+            "rows": [
+                [
+                    {
+                        "__type__": "date",
+                        "__value__": "2014-10-06"
+                    },
+                    10,
+                    "October"
+                ],
+                [
+                    {
+                        "__type__": "date",
+                        "__value__": "2014-10-07"
+                    },
+                    10,
+                    "October"
+                ],
+                [
+                    {
+                        "__type__": "date",
+                        "__value__": "2017-03-08"
+                    },
+                    3,
+                    "March"
+                ],
+                [
+                    {
+                        "__type__": "date",
+                        "__value__": "2024-02-12"
+                    },
+                    2,
+                    "February"
+                ]
+            ]
+        }
+    ],
     [
         "MSUM.Example with ORDER BY",
         {
@@ -3790,9 +3849,9 @@
             ],
             "rows": [
                 [
-                    -1.0,
-                    7.0,
-                    18.0
+                    -3.0,
+                    0.0,
+                    4.0
                 ]
             ]
         }
@@ -5441,7 +5500,7 @@
             ],
             "rows": [
                 [
-                    10.205464964983964
+                    3.8954129979043843
                 ]
             ]
         }
@@ -5457,7 +5516,7 @@
             ],
             "rows": [
                 [
-                    9.770988804733236
+                    3.7295740001000413
                 ]
             ]
         }
diff --git a/lib/dl_formula_ref/dl_formula_ref/functions/aggregation.py b/lib/dl_formula_ref/dl_formula_ref/functions/aggregation.py
index 8ea1fd9b8..277e97c2a 100644
--- a/lib/dl_formula_ref/dl_formula_ref/functions/aggregation.py
+++ b/lib/dl_formula_ref/dl_formula_ref/functions/aggregation.py
@@ -1,3 +1,5 @@
+import datetime
+
 from dl_formula.core.datatype import DataType
 from dl_formula_ref.categories.aggregation import CATEGORY_AGGREGATION
 from dl_formula_ref.examples.config import (
@@ -14,6 +16,8 @@
 
 _ = get_gettext()
 
+_d = datetime.date
+
 _SOURCE_INT_FLOAT_1 = ExampleSource(
     columns=[
         ("City", DataType.STRING),
@@ -35,22 +39,22 @@
 
 _SOURCE_TEMP = ExampleSource(
     columns=[
-        ("Month", DataType.STRING),
+        ("Date", DataType.DATE),
         ("Temperature", DataType.FLOAT),
     ],
     data=[
-        ["January", -8.0],
-        ["February", -4.0],
-        ["March", -1.0],
-        ["April", 7.0],
-        ["May", 14.0],
-        ["June", 18.0],
-        ["July", 22.0],
-        ["August", 19.0],
-        ["September", 13.0],
-        ["October", 5.0],
-        ["November", 1.0],
-        ["December", -4.0],
+        [_d(2019, 3, 1), 5.0],
+        [_d(2019, 3, 2), 0.0],
+        [_d(2019, 3, 3), -3.0],
+        [_d(2019, 3, 4), 1.0],
+        [_d(2019, 3, 5), 4.0],
+        [_d(2019, 3, 6), 5.0],
+        [_d(2019, 3, 7), 1.0],
+        [_d(2019, 3, 8), -6.0],
+        [_d(2019, 3, 9), -6.0],
+        [_d(2019, 3, 10), -4.0],
+        [_d(2019, 3, 11), -2.0],
+        [_d(2019, 3, 12), 0.0],
     ],
 )
 
@@ -372,7 +376,7 @@
                 show_source_table=True,
                 formulas_as_names=False,
                 formula_fields=[
-                    ("Coldest Month", "ARG_MIN([Month],[Temperature])"),
+                    ("Coldest Day", "ARG_MIN([Date],[Temperature])"),
                 ],
             ),
         ),
@@ -394,7 +398,7 @@
                 show_source_table=True,
                 formulas_as_names=False,
                 formula_fields=[
-                    ("Warmest Month", "ARG_MAX([Month],[Temperature])"),
+                    ("Warmest Day", "ARG_MAX([Date],[Temperature])"),
                 ],
             ),
         ),
diff --git a/lib/dl_formula_ref/dl_formula_ref/functions/date.py b/lib/dl_formula_ref/dl_formula_ref/functions/date.py
index b54e09370..047bd012f 100644
--- a/lib/dl_formula_ref/dl_formula_ref/functions/date.py
+++ b/lib/dl_formula_ref/dl_formula_ref/functions/date.py
@@ -236,7 +236,25 @@
     category=CATEGORY_DATE,
     description=_("Returns the number of the month in the year of the specified date {arg:0}."),
     examples=[
-        SimpleExample("MONTH(#2019-01-23#) = 1"),
+        DataExample(
+            example_config=ExampleConfig(
+                name=_("Example with custom first day of the week"),
+                source=_SOURCE_DATE_1,
+                formula_fields=[
+                    ("Date", "[Date]"),
+                    ("Month", "MONTH([Date])"),
+                    (
+                        "Month name",
+                        (
+                            "CASE(MONTH([Date]), "
+                            '1, "January", 2, "February", 3, "March", 4, "April", 5, "May", 6, "June", '
+                            '7, "July", 8, "August", 9, "September", 10, "October", 11, "November", 12, "December", "Undefined")'
+                        ),
+                    ),
+                ],
+                formulas_as_names=False,
+            )
+        ),
     ],
 )
 
diff --git a/lib/dl_formula_ref/dl_formula_ref/functions/string.py b/lib/dl_formula_ref/dl_formula_ref/functions/string.py
index 0863237ee..519db91ed 100644
--- a/lib/dl_formula_ref/dl_formula_ref/functions/string.py
+++ b/lib/dl_formula_ref/dl_formula_ref/functions/string.py
@@ -68,6 +68,7 @@
     description=_("Returns `TRUE` if {arg:0} contains {arg:1}. For case-insensitive searches, " "see {ref:ICONTAINS}."),
     examples=[
         SimpleExample('CONTAINS("RU0891923", "RU") = TRUE'),
+        SimpleExample('CONTAINS("RU0891923", "") = TRUE'),
         SimpleExample('CONTAINS("Lorem ipsum", "abc") = FALSE'),
     ],
 )
diff --git a/lib/dl_formula_ref/dl_formula_ref/locales/en/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po b/lib/dl_formula_ref/dl_formula_ref/locales/en/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
index 0fa5ba3a4..03c881a20 100644
--- a/lib/dl_formula_ref/dl_formula_ref/locales/en/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
+++ b/lib/dl_formula_ref/dl_formula_ref/locales/en/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
@@ -506,13 +506,13 @@ msgid ""
 "functions#parsedatetime32besteffort"
 msgstr ""
 
-msgid "../concepts/data-types.md#geopolygon"
+msgid "../dataset/data-types.md#geopolygon"
 msgstr ""
 
 msgid "https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List"
 msgstr ""
 
-msgid "../concepts/data-types.md#tree-hierarchy"
+msgid "../dataset/data-types.md#tree-hierarchy"
 msgstr ""
 
 msgid "https://en.wikipedia.org/wiki/Unix_time"
diff --git a/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.mo b/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.mo
index 484f9f3a9..0b3ebe4b8 100644
Binary files a/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.mo and b/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.mo differ
diff --git a/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po b/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
index 7cba08880..bb1595ad4 100644
--- a/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
+++ b/lib/dl_formula_ref/dl_formula_ref/locales/ru/LC_MESSAGES/dl_formula_ref_dl_formula_ref.po
@@ -735,14 +735,14 @@ msgid ""
 "functions#parsedatetime32besteffort"
 msgstr ""
 
-msgid "../concepts/data-types.md#geopolygon"
-msgstr "../concepts/data-types.md#geopolygon"
+msgid "../dataset/data-types.md#geopolygon"
+msgstr "../dataset/data-types.md#geopolygon"
 
 msgid "https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List"
 msgstr "https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List"
 
-msgid "../concepts/data-types.md#tree-hierarchy"
-msgstr "../concepts/data-types.md#tree-hierarchy"
+msgid "../dataset/data-types.md#tree-hierarchy"
+msgstr "../dataset/data-types.md#tree-hierarchy"
 
 msgid "https://en.wikipedia.org/wiki/Unix_time"
 msgstr "https://ru.wikipedia.org/wiki/Unix-время"
@@ -2422,8 +2422,9 @@ msgid ""
 "Returns all {arg:0} substrings matching the {arg:1} regex. For regexes with "
 "subgroups, it only works for the first subgroup."
 msgstr ""
-"Возвращает все подстроки {arg:0}, которые соответствуют регулярному выражению "
-"{arg:1}. Для регулярных выражений с подгруппами работает только для первой подгруппы."
+"Возвращает все подстроки {arg:0}, которые соответствуют регулярному "
+"выражению {arg:1}. Для регулярных выражений с подгруппами работает только "
+"для первой подгруппы."
 
 msgid ""
 "Returns a substring {arg:0} that matches the regular expression pattern "