The value of a rare coin, in dollars, is modeled by the function $V(t)=500(1.08{)}^t$, where $t$ is the number of years since its purchase. A new function, $C(d)=500(1+k{)}^d$, is used to model the value of the coin, where $d$ is the number of days since its purchase. Which of the following statements is true about the value of $k$?