The most likely reason is bad design in your DB. From the values you show, it looks like your date column in the DB is VARCHAR or NVARCHAR rather than DATE.
When you do that, your comparisons for dates will be string comparisons, which means the entire comparison is based on the first different character in the two strings. No further characters are checked.
That means that the sort order for "normal intgers" becomes:
And a very similar sort order happens with dates.
The solution is simple: change your DB design, and always store values in appropriate datatypes. Integer values int INT, floating point in FLOAT or DECIMAL, dates in DATE or DATETIME. If you don't you get hassle every time you try to use them...
And as Richard said: Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.
When you concatenate strings, you cause problems because SQL receives commands like:
SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'
The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:
SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;
Which SQL sees as three separate commands:
SELECT * FROM MyTable WHERE StreetAddress = 'x';
A perfectly valid SELECT
DROP TABLE MyTable;
A perfectly valid "delete the table" command
And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.
So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?