I wonder how I can add something like delimiters to make it easier to distinguish between hours, days, weeks, months, years in a time-series plot? Something like vertical lines might already do it, but I have no idea how to add them, and they would need to be added depending on the scale…
Look at adding a shape of type
line to the layout. You can play with the
yref options to change the coordinate system in the x and y directions (e.g.
yref: "paper" would make the supplied coordinates in the y direction on a scale from 0 to 1).
See the examples here