Verily...
Verily, amongst the affairs which has greatly been emphasized in the tradition for us (i.e. the Shias) is the non - fixation of the time of Mahdi's emergence and leaving this matter to Almighty Allah. Yet some traditions mention that those who ordain a time for his emergence are liars.
It can be said that the philosophy of not fixing his reappearing at any time and in any year, month and on any Friday may be due to the following: Firstly, the divine 'Bada' (change) in which we Shias believe plays interference in the matter of Mahdi's emergence and is resolute. Verily, the Will of Allah…
✦ ✦ ✦