To find out what fraction of a day 12 hours represents, we start by recognizing that a full day consists of 24 hours.
Thus, the fraction can be calculated as:
Fraction = (Number of hours)/(Total hours in a day) = 12 hours / 24 hours
When we simplify this fraction:
12/24 = 1/2
This means that 12 hours is equal to 1/2 or one-half of a day.