There are two hours on Friday when Duas are answered: 

1. One is when Friday leader has completed the sermon and the worshippers are prepared for Friday prayer. 

2. The other is the last moments of Friday that is: “When half face of the sun is hidden.” 

Imam Baqir (a.s.) has said:
“On Friday one must keep a time from the beginning of moon until an hour, for the Holy Prophet of Islam (SAW) has said during this hour no servant requests anything from Allah unless his request is granted.”