Is this speaking of a single 24 hour period, or is it one year represented by one day?

Revelation 18:8 Therefore shall her plagues come in one day, death, and mourning, and famine; and she shall be utterly burned with fire: for strong is the Lord God who judgeth her.

(for example:)

Numbers 14:34 After the number of the days in which ye searched the land, even forty days, each day for a year, shall ye bear your iniquities, even forty years, and ye shall know my breach of promise. 

(or like:)

Daniel 9:24a Seventy weeks are determined upon thy people and upon thy holy city,

Because, if it is a single 24 hour period, how would a plague of famine happen in 24 hours?

There are plenty of people who miss meals for a day, and it is not necessarily famine.

However, if the LORD means 24 hours, then that is it, and it is only my understanding that is lacking.