God has not informed anyone of the exact timing of the Day of Judgement. This is knowledge He has kept with Himself. However, God has given us signs which show the nearness of the Day of Judgement. God says, “What are the disbelievers waiting for, other than the Hour which will come upon them unawares? Its signs are already here, but once the Hour has actually arrived, what use will it be then to take heed?” [47:18]
Therefore, God tells us to take heed of the signs of the Day of Judgement so that we can ensure we are working towards what pleases God. There are many signs of the Day of Judgement, however they can generally be split into minor and major signs. The minor signs are many and are those which are events and changes that occur well before the Day of Judgement and continue up to it.
The coming of the Messenger Muhammad and his death were from the first minor signs of the Day of Judgement. Since then, they have been occurring. A sign of the Day of Judgement does not necessarily mean that it is evil but prophecies which show to us the truthfulness of the Messenger Muhammad and remind us to prepare for the Day of Judgement.
Other minor signs of the Day of Judgement include increased ignorance of religion, increase in frequency of earthquakes, indiscriminate murder and killing, time passing by quickly, increase of immorality and bad conduct. To be aware of these and other signs is to know that the Day of Judgement is drawing close and the need to prepare for it.