overlay.nix

rec {
    foo = xs: p: let
      sorted = builtins.sort (x: y: x.startMin < y.startMin) xs;
    in map ({fst, snd}: p fst snd) (super.lib.zipLists sorted (builtins.tail sorted));

    verifyTime = times: foo times (x: y: x.startMin + x.lenMin <= y.startMin);
}