At least in this case, though it wasn't going to be very clear to Char, Bulba's silence on the issue wasn't because he was intending on holding out on him. It was just probably easier to try and wrap your mind around something unfamiliar when you had a better rest, and Bulba was aware that he had sort of screwed up the opportunity for this to happen to Char. One convoluted conversation per overtaxed body at a time.

"Uh... I'm not sure," Bulba admitted. "I haven't been paying attention to what time it is... A little while, though."