Christmas is nearing, and Santa has upgraded his sled to OP levels. His sled is now a gigantic truck pulled by robotic reindeer, and which can travel at 1c, or at 100% the speed of light (Hi handwavium). This is because Santa no longer has just one planet i.e. Earth to deliver gifts to, but he now has to deliver to multiple planets, where humans have settled on, such as Mars, Venus etc.
Santa also has another gift delivery destination: Saturn.
On Saturn, multiple cloud cities have formed, the smallest ones with a population of just a few hundreds, while the largest cloud cities can host up to 1 billion people. This means that there is a high prospect of gift-giving to the Saturnians, and expanding Santa's base to beyond Earth.
This special Christmas, Earth and Saturn are at their closest approach, about 750 billion miles apart.
However, here is one major problem.
In this universe, handwavium cannot be used to make warp drives or be used for FTL travel. That means that Santa's sled can at max speed, travel at 100% of the speed of light. That sounds like a lot.
But in reality, that would mean that Santa would take about 1 hours to reach Saturn. That sounds negligible. But the catch here is that one day on Saturn lasts only 10 hours. Which means that nighttime lasts just 5 hours. This means that an average Saturnian Human would sleep for only 4 hours each Saturnian day. Santa is not someone who wants to be public, he wants to gift people (including adults and kids) anonymously, and quietly, but there is the probability that atleast 1 or 2 out of 4 people might notice Santa approaching Saturn on his sled. Santa wants to avoid this, he prefers to gift his presents in the dead of night, when nobody's awake. Thus Santa needs to approach as quickly as possible, so that he can reach Saturn by midnight Saturnian time.
How does Santa give gifts to the Saturnians, albeit anonymously?
Santa cannot time-travel and reach Saturn quickly.
Santa doesn't teleport.
The Saturnian day lasts 10 hours, so the clocks used in Saturn are 5-hour clocks, with Ante Meridien lasting 5 hours, and Post Meridien lasting 5 hours as well. So instead of 12 AM/PM like on Earth, the Saturnian clock follows the 5 AM/PM format.
Santa needs to give his gifts at midnight, which in Saturnian Clock interprets as between 4 PM to 1 AM