Regularity of emotional functioning of a human in specifi c time can be determined by
cycles characterised by psychophysiological and social changes. The objective of the research was to
establish whether the population subjected to the research-related tests experienced circadian and
circaseptan mood variability and, if this relation has been confi rmed, describe the latter. Mood was
tested by means of Positive and Negative Affect Scale (Watson, Clark & Tellegen, 1988). Subjects
judged their mood by means of two indicators (positive and negative affect), for one week, on a daily
basis, at 3-hour intervals. Circadian and circaseptan variability was assessed by comparing averaged
results obtained from all measurements carried out at specifi c times of the day and days of the week.
The assessment of internal group differences was performed with the repeated measures analysis of
variance. The result obtained in the tests indicated the existence of circadian differences of positive
affect as well as circaseptan differences in relation to positive and negative affect.