The entire concept of DTA is based on accrual basis of accounting.
When we recognise DTA we are actually recognising the following fact
1. That there is an item of Expenses (Already recognised in Accounts / Will be allowed in Tax in future years) on which we will get tax benefit in future in the year of allowance OR
2. That there is an item of Income (Already recognised in Tax / Will be recognised in accounts in future years) on which tax already paid hence no tax will be required to be paid in future year, hence a tax benefit
However please note that in both of above case you will be able to realise these futurte benefits only if You have future income against which such future allowance can be adjusted.