A clock pendulum made of invar has a period of $0.5\,\text{s}$ at $20\,^{\circ}\text{C}$. If the clock is used in a climate where the temperature averages $30\,^{\circ}\text{C}$, how much time does the clock lose in each oscillation? (For invar, $\alpha = 9 \times 10^{-7}\,/^{\circ}\text{C}$, $g = \text{constant}$)