DATETIMEFROMPARTS (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
This function returns a datetime value for the specified date and time arguments. For more information about valid ranges, see datetime.
Transact-SQL syntax conventions
DATETIMEFROMPARTS ( year , month , day , hour , minute , seconds , milliseconds )
An integer expression that specifies a year.
An integer expression that specifies a month.
An integer expression that specifies a day.
An integer expression that specifies hours.
An integer expression that specifies minutes.
An integer expression that specifies seconds.
An integer expression that specifies milliseconds.
datetime
DATETIMEFROMPARTS returns a fully initialized datetime value. DATETIMEFROMPARTS raises an error if at least one required argument has an invalid value. DATETIMEFROMPARTS returns NULL if at least one required argument has a NULL value.
This function is capable of being remoted to SQL Server 2012 (11.x) servers and later versions. It isn't remoted to servers running SQL Server 2012 (11.x) and earlier versions.
SELECT DATETIMEFROMPARTS ( 2010, 12, 31, 23, 59, 59, 0 ) AS Result;
Here's the result set.
2010-12-31 23:59:59.000