Not sure if I'm overlooking something obvious, but given the possibility to reduce dates/times into simple integers (doable according to the example), you shoul

Not sure if I'm overlooking something obvious, but given the possibility to reduce dates/times into simple integers (doable according to the example), you should be much faster sorting the data and using and intelligent comparing than allocating a tree with O(n•logn) nodes. Those heap allocation should slow you down drastically, at least for any problem size where linear work is still efficient enough.