At what day of trek you reach chrandratal lake in Hampta pass

I wanted to know on which day we usually reach Chandratal Lake during the Hampta Pass trek—Day 4 or Day 5? Also, what is the probability of reaching Chandratal on Day 4 and then reaching Manali by around 1:00 PM the next day?

I have a train from Delhi at 8:00 AM the following day, so I need to plan and book my bus accordingly. I noticed that TTH recommends booking a bus only after 8:00 PM