date is valid or not in SQL Server Store Procedure

you can simply use ISDATE(expression)

 

This is the inbuilt function of SQL Server you just need to pass the string or datetime value it will give the 1 or 0 if founds date 1 else return 0.

 

for more information you can refer to this link

https://docs.microsoft.com/en-us/sql/t-sql/functions/isdate-transact-sql