Long-term X-ray variability of SAX J2103.5+4545 as seen by the all-sky monitors RXTE/ASM (black) and SWIFT/BAT light curves (red). The original one-day resolution light curves were rebinned to a bin size equal to the orbital period (P_orb = 12.67 d). The blue and orange vertical lines indicate the epochs when the BVRI magnitudes were below (brighter) and above (fainter) the average, respectively.