Add getdate functions recommendations

Author: ktaranov

SQL Server Name Convention and T-SQL Programming Style.md

@@ -201,15 +201,18 @@ More details about SQL Server data types and mapping it with another databases a
 
 This is only recommendations! But it is consistent for choosing only 1 function from possibles alterntives and use only it.
 
-| Not Recommended | Recommended | When and Why | More details |
-|-----------------|-----------------|------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
-| [`!=`][12] | [`<>`][12] | `<>` is [`ANSI`], `!=` not `ANSI`, [`<>` and `!=` are identical][13] | [13] |
-| [`CONVERT`][10] | [`CAST`][10] | `CAST` is [`ANSI`] | [14],[15] |
-| [`ISNULL`] | [`COALECSE`] | `COALECSE` is [`ANSI`] and supports more than two arguments, `ISNULL` has dangerous behaviour with possibility to implicit triming string | [16],[17] |
-| [`DATEDIFF`] | [`DATEADD`] | The predicate `MyDateTime < DATEADD(SECOND, -1, GETUTCDATE())` syntax is [`SARGable`] | [18],[19] |
-| [`SELECT`] | [`SET`] | Using `SET` (is [`ANSI`]) instead of `SELECT` when assigning variables due to properly work with `Msg 501 Subquery returned more than 1 value` | [20],[21],[22] |
-| [`STR`] | [`CAST`][10] | `STR` is not [`ANSI`], extremly slow, don't use more than 15 digits, and has rounding problem - use `CAST` plus concatenate instead `STR` | [23] |
-| [`ISNUMERIC`] | [`TRY_CONVERT`] | `ISNUMERIC` can often lead to data type conversion errors, when importing data. For SQL Server below 2012 use `WHERE` with `LIKE`. | [24] |
+| Not Recommended | Recommended | When and Why | More details |
+|-----------------|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
+| [`!=`][12] | [`<>`][12] | `<>` is [`ANSI`], `!=` not `ANSI`, [`<>` and `!=` are identical][13] | [13] |
+| [`CONVERT`][10] | [`CAST`][10] | `CAST` is [`ANSI`] | [14],[15] |
+| [`ISNULL`] | [`COALECSE`] | `COALECSE` is [`ANSI`] and supports more than two arguments, `ISNULL` has dangerous behaviour with possibility to implicit triming string | [16],[17] |
+| [`DATEDIFF`] | [`DATEADD`] | The predicate `MyDateTime < DATEADD(SECOND, -1, GETUTCDATE())` syntax is [`SARGable`] | [18],[19] |
+| [`SELECT`] | [`SET`] | Using `SET` (is [`ANSI`]) instead of `SELECT` when assigning variables due to properly work with `Msg 501 Subquery returned more than 1 value` | [20],[21],[22] |
+| [`STR`] | [`CAST`][10] | `STR` is not [`ANSI`], extremly slow, don't use more than 15 digits, and has rounding problem - use `CAST` plus concatenate instead `STR` | [23] |
+| [`ISNUMERIC`] | [`TRY_CONVERT`] | `ISNUMERIC` can often lead to data type conversion errors, when importing data. For SQL Server below 2012 use `WHERE` with `LIKE`. | [24] |
+| [`GETDATE`] | [`SYSUTCDATETIME`] | Daylight Saving Time and other factors can play havoc with our dates and times, rounding to the nearest 3 milliseconds. | [25] |
+| [`GETUTCDATE`] | [`SYSUTCDATETIME`] | Daylight Saving Time and other factors can play havoc with our dates and times, rounding to the nearest 3 milliseconds. | [25] |
+| [`SYSDATETIME`] | [`SYSUTCDATETIME`] | Daylight Saving Time and other factors can play havoc with our dates and times, rounding to the nearest 3 milliseconds. | [25] |
 
 [12]:https://docs.microsoft.com/sql/t-sql/language-elements/comparison-operators-transact-sql
 [13]:https://dba.stackexchange.com/a/155670/107045
@@ -234,6 +237,10 @@ This is only recommendations! But it is consistent for choosing only 1 function
 [`ISNUMERIC`]:https://docs.microsoft.com/en-us/sql/t-sql/functions/isnumeric-transact-sql
 [`TRY_CONVERT`]:https://docs.microsoft.com/en-us/sql/t-sql/functions/try-convert-transact-sql
 [24]:https://www.red-gate.com/hub/product-learning/sql-prompt/sql-prompt-code-analysis-avoid-using-isnumeric-function-e1029
+[25]:https://bornsql.ca/blog/dates-times-sql-server-t-sql-functions-get-current-date-time/
+[`GETDATE`]:https://docs.microsoft.com/sql/t-sql/functions/getdate-transact-sql
+[`GETUTCDATE`]:https://docs.microsoft.com/sql/t-sql/functions/getutcdate-transact-sql
+[`SYSDATETIME`]:https://docs.microsoft.com/sql/t-sql/functions/sysdatetime-transact-sql
 
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