Hard to say. Node Pool was launched on April 20th. The next day Constant made the following announcement via email:
As you know, Constant prioritizes a smooth user experience, which is why we typically offer 24 hour withdrawals.
We’re able to do this because we keep a liquid reserve of PRV that isn’t locked up in nodes. Due to the high volume of withdrawals, this reserve is running low, and our nodes must now be unstaked.
Unstaking is random on the Incognito Chain. It can take anywhere from 4 hours to 2 weeks. 1-2 weeks is a generous estimate that takes this into account.
2 weeks would fall right around May 4th.