CTFS Time Shifting Property
If x(t) has CTFS coefficients $ a_k $ and y(t) has CTFS coefficients $ b_k $,
then the Fourier series coefficients $ b_k $ of the resulting signal y(t) = x(t - $ t_0 $)
may be expressed as $ b_k = \left ( \frac{1}{T} \right ) \int \limits_T x \left ( t - t_0 \right ) e^{-j k w_0 t}\, dt $.