Given: Frequency of the simple harmonic oscillator $f=1 \mathrm{Hz}$ , and phase $\theta =1 \mathrm{radian}$

The expression of the phase of a simple harmonic oscillator is stated as $\theta =\omega t$, where $\omega$ is the angular velocity, $t$ is the time.

$\omega =\frac{\theta }{t}$, Since $\omega =2\pi f=2\pi$

Thus time, $t=\frac{\theta }{\omega }=\frac{1}{2\pi }$

Hence, the shit in time should be $-\frac{1}{2\pi } \mathrm{s}$.