Values of the rotation periods per 90-day quarters returned by the ACF, PS, GLS, and GPS methods. The analysis is performedfor the VIRGO (top panels) and TIM (bottom panels) data. Pale orange shaded areas cover the period range of [23–34] days (see Sect. 3.5 for details). Information about the ranges of rotation period values obtained by each method for different instruments is shown near the top of each panel.