The Senate convenes for Trump's impeachment trial at 1pm local time and ends at 9pm local time.
Why these weird hours? The majority of the population I know begins work at around 9am and finish at 5-6pm. It sounds pretty strange to arbitrarily shift the working hours back by four hours. Yes, they are still working "standard hours" in terms of total hours worked, but by getting home later at night, they also can't do things like spend time with their partners or children (if their partners/children have more normal working hours).
A 1pm-to-9pm shift is more standard for fields such as retail, because there are shoppers who shop after working hours and it's important to keep the store open then. However I don't see how this applies to the Senate, who are after all setting their own rules.
Related: Why would the Senate adopt such tiring impeachment trial rules? However, the answers to that question don't seem applicable here: even if it's important for political reasons to force both sides to give all their evidence in 3 days, I don't see why they can't have a 9am-to-5pm Senate session instead of 1pm-to-9pm, which would achieve the same thing in the same amount of time.