>I could add a identity field as autoincrement.
>But what happens when I want to insert a backdated entry which has to be sorted datewise in ledger report and the balances calculated in that order.
PMFJI, but all you need to do in this case is insert the record with the correct (backdated) date and order by date in the ledger report and balance algorithm.

The Identity field is used as a unique identifier or primary key. It should not be used to sort anything.