I think it was 11 pm because he tells Scrooge that he will be visited by 3 ghosts starting at midnight
Marley tells Scrooge to expect three more spirits to visit him that night.
Marley appeared to Scrooge and warned him about changing his behavior. Marley also told Scrooge he would be visited by three ghosts.
Marley told of three ghosts
When Marley's ghost visited Scrooge he warned him about the ghosts and his behaviour.
Marley was very much like Scrooge in life. However, Marley having suffered seven years of torment in the after life sees that that Scrooge is also destined for everlasting torment after his death and he seeks to redeem himself if only slightly by warning his friend Ebenezer
scrooge's partner Marley visited him first
Three ghosts
Three were foretold
Jacob Marley was Ebenezer Scrooge's business partner in Charles Dickens' "A Christmas Carol." He was the very first ghostly visitor to Scrooge on Christmas Eve to tell Scrooge that he would be visited by three other spirits that night. The opening sentences of the book are "Marley was dead: to begin with. There is no doubt whatever about that."
Jacob Marley tells Scrooge that three ghosts will visit him to warn him of the consequences of his actions and show him the errors of his ways. The three spirits represent the past, present, and future, aiming to prompt Scrooge to reflect on his life and make a change before it's too late.
He showed him aspects of the past, present, and future. He made Scrooge realize what was happening in the lives of his poor worker. He showed him (Scrooge) himself. He saw how cruel he was and what would happen if he did not change his ways. He saw too much and decided to change his and Tiny Tim's future.To tell Scrooge his bad deed an wrong doings.
This was Marley telling Scrooge that he (Marley) was allowed to come back to Scrooge to tell Scrooge of his inpending eternal life of torment should he not make changes to the way he lives his life now and sees mankind as his business not just the money he can get from them