Notion Timeline database

I try to recreate this timeline, for the infinite horizontal scroll I have an idea, but I do not understand how they manage to attach the projects to a fixed date and position when the timeline scrolls. Another technical challenge that I can't conceive of is the fact that the size of the rectangle is exactly the size of that duration.

I would like to create this component without using a timeline near designed using Reactjs.

dayjs and the only beginning I could find