Different timescales of the daily amplitude of the geomagnetic Y component during quiet period (Sq(Y)) over several solar cycles at 25 mid-low latitudes observatories were analyzed. The annual mean (Sq₀), annual (Sq₁) and semiannual (Sq₂) components were separated from Sq(Y) by means of Fourier analysis method. No obvious distinction is found for the morphology of the spatial distribution of these Sq(Y) components during solar quiet and active periods, except that they are more intense in high solar activity. Sq₁(Y) exhibits a remarkable longitudinal inequality, which is much stronger around Eurasia and Australia anomaly zones and weaker around South Atlantic Ocean anomaly zones. The positive correlation between Sq₀(Y) and geomagnetic vertical component Z suggests that the convection electric fields in the dynamo region play a key role in controlling annual mean (Sq₀). On the other hand, the Sq₁(Y) exhibits a positive correlation with geomagnetic horizontal component H, implying the inter-hemispheric field-aligned currents (IHFACs) may contribute to difference of the annual variation amplitude at different observatories. The Sq₂(Y) is most prominent in the South Atlantic Ocean anomaly (SAO) region. It is possible the stronger ionospheric conductivity in the dynamo region contribute to the remarkable semiannual variation at SAO region.