A particular type of fundamental scheduling problem has in the past years gained attention from researchers from several different fields. In the most basic version of the problem, the pinwheel scheduling problem, we are given a set of tasks, each of which requires to be scheduled repeatedly with a given minimum frequency. Main questions are (a) under what conditions a perpetual schedule provably exists that respects these frequencies, and (b) how to produce such a schedule efficiently.

Perhaps most notably, the over-30-year-old "Pinwheel density conjecture" was finally proven in 2024. Many questions about its extensions, variants, possible applications, as well as a simplification of the computer-assisted proof, however, remain open.

In this Dagstuhl Seminar, we aim to, for the first time, bring the researchers active in this area together and add researchers from outside whose work has (or may have) connections to the aforementioned types of problems: researchers from the fields of real-time scheduling, complexity theory, and online algorithms. Utilizing the current momentum, we believe that we can solidify and shape a subfield, identify and start working on new directions, and tackle open problems.

Creative Commons BY 4.0

Kunal Agrawal, Akitoshi Kawamura, Kevin Schewior, and Sebastian Wild

This seminar qualifies for Dagstuhl's LZI Junior Researchers program. Schloss Dagstuhl wishes to enable the participation of junior scientists with a specialisation fitting for this Dagstuhl Seminar, even if they are not on the radar of the organizers. Applications by outstanding junior scientists are possible until Friday, May 29, 2026.