Convert date in varbinary encrypted column back to date in sql server

Please i need help with sql server data type conversion.

So i inserted this date '2022-12-01 after encrypting into a varbinary column DateAllowed.

INSERT INTO Tablename (Username, Password, UserType, DateAllowed)

VALUES ('Username', EncryptByKey(KEY_GUID('SymmetricKey'), 'Password'), EncryptByKey(KEY_GUID('SymmetricKey'), 'exampletext'), EncryptByKey(KEY_GUID('SymmetricKey'), '2022-12-01'));

It inserted successfully but when i select DateAllowed by decrypting and try to convert the decrypted text to date i get this error.

Msg 241, Level 16, State 1, Line 4

Conversion failed when converting date and/or time from character string.

The Query i used is below

OPEN SYMMETRIC KEY RMSSQLSymmetricKey DECRYPTION BY PASSWORD = 'Password';

SELECT CONVERT(date, DecryptByKey(DateAllowed)) AS 'DateAllowed1' FROM Tablename;

The interesting part is, if i use varchar i get the date back

SELECT CONVERT(varchar, DecryptByKey(DateAllowed)) AS 'DateAllowed1' FROM Tablename;

The problem with this too is that when i get the date as varchar C# program i make in visual studio does not recognise as date datatype even if i try to convert it to DateTime.

Please i need this solved urgently.

How can i convert the Date that is in varbinary back to date.