Four times of breaking samadhi

The four times of breaking samadhi are:

1. sunrise,
2. sunset,
3. noon, and
4. midnight.

During a retreat, one should avoid carrying out a recitation session during these four times. Instead, these four times could be opportunities to have breaks between sessions—i.e., to have a meal, perform other activities, and so on.

Source

RigpaWiki:Four times of breaking samadhi