I have read that the "doors of mercy" are open until the day when the Sun changes direction. However recently I heard that the doors of mercy will shut when a smoke enters the Earth as a sign that Judgement day is near. I have also heard that the doors of mercy shut when Dajjal comes.
The reason for this is that you have had your chance to repent but you have still gone astray so now your chances are up as it is clear what is the truth. But aren't these sign for that very purpose? To make you realize the truth and believe and repent?
Also, as the doors of mercy have shut, people cannot ask for forgiveness anymore but do they still have to keep up with the good deeds and will they still get sins for not praying or doing something bad? Isn't this a harder test as there are no chances anymore? What about the people who were beleivers?