Typically, a float session lasts an hour (but can be shorter or longer). However, when you’re floating in darkness with no reference points and no smartphone to check, you can quickly lose sense of time.
That means your 60-minute session can end up feeling like 15-minutes, even when you’re sure you didn’t drift off to sleep during the session. “In a float tank, you lose all sense of time. A minute can feel like an hour, and vice-versa,” says a writer for Slate.com.