Create documentation for DATEFORMAT

content/en/docs/refguide/modeling/domain-model/oql/_index.md

@@ -43,6 +43,7 @@ OQL is under constant development so some expressions and features are not avail
 | Feature | Mendix Version |
 | --- | --- |
 | DATEADD | 11.9.0 |
+| DATEFORMAT | 11.12.0 |
 | DATEPARSE | 11.10.0 |
 | DATETRUNC | 11.9.0 |
 | LOCATE | 11.9.0 |

content/en/docs/refguide/modeling/domain-model/oql/oql-expression-syntax.md

@@ -1022,6 +1022,57 @@ SELECT Revenue : DATEDIFF(MONTH, End, Start ) as avg_revenue FROM Sales.Period
 The way the difference is calculated depends on the database. The `YEAR` difference between "2002-01-01" and "2001-12-31" will be `1` with some databases and `0` with others.
 {{% /alert %}}
 
+### DATEFORMAT {#dateformat-function}
+
+The `DATEFORMAT` function formats values of type Date and time as strings using a specified pattern.
+
+This function was introduced in Mendix version 11.12.0.
+
+#### Syntax
+
+The syntax is as follows:
+
+```sql
+DATEFORMAT ( expression , pattern )
+```
+
+`expression` is a value of type Date and time.
+
+`pattern` is a pattern used to convert `expression` to a string value. Only string literals are allowed.
+
+#### Pattern Syntax
+
+The `DATEFORMAT` OQL function uses the same pattern syntax as date parsing functions in Studio Pro, see [Parse and Format Date Function Calls](/refguide/parse-and-format-date-function-calls/).
+
+#### Limitations and Database-Specific Differences
+
+When an OQL query is executed, `DATEFORMAT` is converted to the corresponding database function. Due to implementation specifics of database engines, different limitations apply:
+
+1. Format letters `u`, `F`, `G`, `k`, `K` are not supported.
+2. SQL Server does not support format letters `D`, `Y`, `w`, `W`.
+3. MySQL and MariaDB do not support format letters `S` and `W`.
+4. SAP HANA does not support format letters `Y` and `w`.
+5. Format letter `h` results in different values per database:
+
+    1. HSQLDB uses zero-based indexing and returns values `0` to `11`
+    2. Other databases use one-based indexing and return values `1` to `12`
+
+6. In addition to listed limitations, there are other implementation differences between database engines.
+
+{{% alert color="warning" %}}
+Always test usages of `DATEFORMAT` with the database engine on which your app runs. OQL queries with `DATEFORMAT` may return different results in HSQLDB and in the production database.
+{{% /alert %}}
+
+#### Examples{#oql-dateformat-example}
+
+Let's assume that an object has an attribute `StartDate` of type Date and time with value `30 December 2025 13:02:15.300`.
+
+| Function call                                 | Result | Notes |
+|--------------|------|-----|
+| `DATEFORMAT(StartDate, 'dd MMM yyyy')`       | 30 Dec 2025 |  |
+| `DATEFORMAT(StartDate, 'yyyy-MM-dd hh:mm:ss a')`       | 2025-12-30 01:02:15 PM |  |
+| `DATEFORMAT(StartDate, 'EEE-ww-YYYY')`       | Tue-01-2026 | ISO date format is not supported by SAP HANA and SQL Server. `w` stands for the ISO week number, and `Y` stands for ISO year. |
+
 ### DATEPARSE {#dateparse-function}
 
 The `DATEPARSE` function parses string values to Date and time using a specified pattern.
@@ -1050,6 +1101,7 @@ When an OQL query is executed, `DATEPARSE` is converted to the corresponding dat
 
 1. Format letters `u`, `F`, `G`, `k`, `K` are not supported.
 2. MySQL and MariaDB do not support format letters `S` and `W`.
+2. SAP HANA does not support format letters `Y` and `w`.
 3. For SQL Server, `DATEPARSE` accepts only patterns that match SQL Server styles 0 to 7, 9 to 13, 100 to 107, 109 to 113, 120 and 121. See [SQL Server documentation](https://learn.microsoft.com/en-us/sql/t-sql/functions/cast-and-convert-transact-sql?view=sql-server-ver17#date-and-time-styles) for the list of supported styles.
 4. Format letter `h` accepts different ranges of values per database: