Nauru [wiki] is the world's smallest island nation, the smallest independent republic, and the only republic in the world without an official capital. Nauru only has one significant source of income: phosphates from thousands of years' worth of guano or bird droppings.
We may have the same friends. The same ones who take NyQuil when they're not really sick, just to help them sleep. So they're taking it for the diphenhydramine (Benadryl), which is much more cheaply purchased alone and as a generic. DayQuil is dextromethorphan, acetaminophen, and phenylephrine.
DayQuil was introduced in 1974 under the name  DayCare  and is currently advertised for daytime use because of its non-drowsy active ingredients. The brand name was reintroduced as DayQuil in 1992. DayQuil's nighttime counterpart, NyQuil, is also available for the relief of cold and flu symptoms during the night. These products are not intended to cure the common cold or the flu.