The phrase "diurnal pattern" refers to the regular cycle or routine that occurs during a 24-hour period, particularly in relation to natural processes or behaviors that follow the day and night cycle. Full definition
Wikipedia: John Harvey Kellogg Kumari M, Shipley M, Stafford M, Kivimaki M. Association of diurnal patterns in salivary cortisol with all - cause and cardiovascular mortality: findings from the Whitehall II study. (wellnessmama.com)
The four - point urine test allows physicians to diagnose whether there is a flat diurnal pattern, which is considered worse than smoking according to the Whitehall Study, [1] and may be a marker of greater mortality in those with breast cancer. (saragottfriedmd.com)
A seasonal diurnal pattern is expected to return on Friday. (costaricantimes.com)