The new data is used immediately (it is not saved: reloading brings back the included data).
What is that line of lights in the sky?
If you saw a row of bright dots moving together across the sky, it was almost certainly a Starlink train: a group of SpaceX satellites launched together on the same rocket. During the first days they travel very close to each other, so they look like a line. Over the following days they slowly climb to their final orbit, spread out and stop looking like a train.
When can you see the Starlink train?
It is only visible when your sky is already dark while the satellites, far higher up, are still lit by the Sun. That happens shortly after sunset or shortly before sunrise. This page calculates every pass from your city and marks in green the ones that will look good: at night, with the train sunlit and more than 30° above the horizon.
How to see it
Choose your city in the passes table, check where on the horizon it appears and at what time, and go out a few minutes early to a place with little light. It is visible to the naked eye, no telescope needed. The best trains are those in the first days after a launch: the calendar lists the upcoming SpaceX launches.
About Starlink Trains
Starlink Trains is a free website, with no sign-up, that tracks Starlink satellite trains and SpaceX missions live and tells you when and where to see them from your city. It updates itself every morning with the latest orbital data.