Although its location has not been established, circaseptan (about seven days) and circasemiseptan (about half week) clocks may exist to adapt the organism to events that happen once and twice a week.
Mapping of circaseptan and circadian changes in mood.
A larger scale longitudinal experiment seems possible, applying the personalized heart rate techniques that we have adopted at various points in the year on both weekdays and weekend days; this would test for possible circadian, circaseptan
and seasonal effects in Tunisian society, and would help to establish causality in the relationships that we have observed.
(about weekly) and circannual (about yearly) rhythms are examples of infradian rhythms.