Circadian pattern of seizure distribution in C57BL/6J mice during the long-term video-EEG recording period in mice previously exposed to eight repeated flurothyl-induced generalized seizures (flurothyl concentrations, 10% and 100%). The total number of SSEs detected in C57BL/6J mice were grouped by weeks and were further categorized into whether the seizures occurred during the day [lights on (inactive period of mice), 7:00 A.M. to 7:00 P.M.] or night [lights off (active period of mice), 7:00 P.M. to 7:00 A.M.]. Spontaneous seizures occurred significantly more during the lights-on period than in the dark period (*p < 0.05). The x-axis represents the duration of the recording period by weeks, whereas the y-axis represents the percentage of total SSEs that occurred during either day (white bars, lights on) or night (black bars, lights off).