Erwin Schrödinger, the Nobel-prize-winning Austrian physicist, was able to make major contributions to the fields of quantum mechanics, general relativity, and color theory during his lifetime. There was only one caveat: He was not able to make those contributions ... in the morning.

“He couldn’t work in the mornings at all,” his wife, AnneMarie, said in an interview. “The [Max] Planck lectures—as you know, it was 30 or 40 years ago that Planck was in Berlin—were given in the morning from nine to ten. When he got this very, very honorable call to Berlin, he wrote first thing and said, ‘I’m very sorry, but I can’t keep the lecture hours because I can’t work in the morning.’ ... They understood, and changed it to the afternoon—two lectures, one after the other—on two days.”

Ah, to be so famous that a major university rearranges its events just so you can hit the snooze button.

Scientists would later classify people like Schrödinger as “owls”—people who prefer to wake up late and are more alert in the evenings. It’s one of two basic chronotypes, or preferred sleep schedules. The other is “larks,” or crazy people those who prefer early mornings.

But now, scientists in Russia are proposing that there are actually four chronotypes: In addition to early and late risers, they say, there are also people who feel energetic in both the mornings and evenings, as well as people who feel lethargic all day.

For a study forthcoming in the journal Personality and Individual Differences, biologist Arcady Putilov and his colleagues at the Siberian Branch of the Russian Academy of Sciences asked 130 people to stay awake for 24 hours. The subjects filled out questionnaires about how awake they felt, their sleep patterns, and how well they had functioned during the previous week.

The results showed that among them were 29 larks, who showed higher energy levels at 9 a.m. than at 9 p.m., and 44 owls, for whom the opposite was true. The owls also went to bed about two hours later, on average, than the larks. But the rest of the group fell into neither of these patterns. As BPS Research Digest puts it:

There was a “high energetic” group of 25 people who reported feeling relatively sprightly in both the morning and evening; and a “lethargic” group of 32 others, who described feeling relatively dozy in both the morning and evening.

Both the lethargic and energetic participants went to bed and woke up somewhere between the owl and lark times. The energetic people slept about a half-hour less overall than the other three groups, netting about 7.5 hours of sleep each night.

So next time, rather than complain to your co-workers that you’re “always tired,” just let them know that you’re part of a newly discovered chronotype that is, in essence, all out of awakes to give.

The next big question is, obviously, what bird names to assign these two new groups. Lazy Bird and hummingbird? The albatross and the peregrine falcon? How many of these are already taken by indie bands?