When is the time of response mentioned in this following hadith?

I have read a hadith that says, every night there is an hour when no Muslim asks Allah of anything and he will be given that. Can anyone tell me is there any record or authentic opinion about when this time might be? I have read about the hour of response on Friday, but don't know about the hour of response at every night. Is it the last third of night as Allah(SWT) descends to the last heaven described in another hadith? Or is it referring some different time period of the night?