  In chiral magnets a magnetic helix forms where the magnetization winds around
a propagation vector $\mathbf{q}$. We show theoretically that a magnetic field
$\mathbf{B}_{\perp}(t) \perp \mathbf{q}$, which is spatially homogeneous but
oscillating in time, induces a net rotation of the texture around $\mathbf{q}$.
This rotation is reminiscent of the motion of an Archimedean screw and is
equivalent to a translation with velocity $v_{\text{screw}}$ parallel to
$\mathbf{q}$. Due to the coupling to a Goldstone mode, this non-linear effect
arises for arbitrarily weak $\mathbf{B}_{\perp}(t) $ with $v_{\text{screw}}
\propto |\mathbf{B}_{\perp}|^2$ as long as pinning by disorder is absent. The
effect is resonantly enhanced when internal modes of the helix are excited and
the sign of $v_{\text{screw}}$ can be controlled either by changing the
frequency or the polarization of $\mathbf{B}_{\perp}(t)$. The Archimedean screw
can be used to transport spin and charge and thus the screwing motion is
predicted to induce a voltage parallel to $\mathbf{q}$. Using a combination of
numerics and Floquet spin wave theory, we show that the helix becomes unstable
upon increasing $\mathbf{B}_{\perp}$ forming a `time quasicrystal' which
oscillates in space and time for moderately strong drive.
