How long are nightly whls available

how long are nightly whls available? i noticed that the whl version 2.1.0.dev20230602+cpu was taken down today:

CC @malfet who might know the life time of the nightly binaries.

There aren’t really taken down, just removed from the index after 60 days, see

But one can still download the wheel, i.e.
curl -OL will get you 2.1.0.dev20230602 wheel for Python-3.10