How late is too late to email POIs?

[bardolatry]

I've been really anxious about this step in particular, and I'm now worried I've put it off too late. For a traditional email of interest, how long before the application deadline would you say is too late?

[loffire]

I'm not sure if I'm a good authority on this (I should have a PhD on procrastination by now), but if it's any comfort, I just sent out some emails to some POIs I recently shortlisted after cutting some others

[phyanth]

If you're going to send emails out, I would do it ASAP. We're nearing the end of the semester, so professors are going to be gearing up for finals, conferences (in some cases), and the holidays. Just don't be discouraged if it takes a while to hear back or you don't hear anything; they may be too busy and forget.