Specifying the signs before the time of reappearance has its own advantages and benefits. Since the time of reappearance is not known to people, the only way to describe the reappearance is to describe its signs.
Observing any of the mentioned signs strengthens one's faith in the reappearance of Imam (AS) and increases his anticipation. Although whatever indications were given by the Imams (AS) regarding the incidents which are to occur are totally based on the previous decreed decisions, they should not be ignored and should not be considered as insignificant. These signs were not given for the purpose of predicting the time of reappearance, or for urging people to search the scientific data to estimate the time of the occurrence of the sign itself. They, rather, become a reminder for people only after they occur miraculously. Once a sign occurs, the believers realize that it was amongst the signs that they were foretold, and thus, their faith and confidence will increase, and they will realize that the time of reappearance is closer than ever.
Keeping in mind the issue of al-Badaa, all the mentioned signs before his arrival, even if they finally occur, they may happen miraculously in an unpredictable manner. As we have seen in the second section, some of the signs such as an eclipse of the moon at the end of the month can only happen miraculously. Even for some other signs that can occur naturally and can be predicted by the available physical information, they may still occur supernaturally and thus their predicted schedules may be proven wrong. The more interesting observation is that, one of the mentioned signs at the end of the time is the rising of the sun from the west, which shows that Allah will miraculously change the direction of the heavenly bodies, and thus, all astronomical data will change according to the new movements. This means that all timely predictions based on the available astronomical data will be proven false due to this single miracle of Allah.
Thus, instead of worrying about the time of the occurrence of the cancelable or at least the unpredictable signs before the rising of Imam al-Mahdi (AS), one should care about keeping faith in the Imam (AS) and following his Sunna. Only in that way, will one be safe from the afflictions of the end of time no matter if those signs finally occur or not. If some the signs occur he will gain more hope and energy that the appointed time is fast approaching, and if he did not observe the signs he will still remain hopeful to receive the Imam (AS) because he believes that Allah is never restricted by His creation including His previous will and has power to do all things at any moment.
Sources: alhassanain.com
source : tebyan
