A lot of biphasic sleepers claim to do one 4.5h session and one 1.5h session, and that it's like a hack on getting less sleep. You might be one of those. I need

A lot of biphasic sleepers claim to do one 4.5h session and one 1.5h session, and that it's like a hack on getting less sleep. You might be one of those. I need 8 in either mode. Earplugs and a sleep mask are helpful if you're having trouble in the second phase.